This question, in slightly varying word construct, tends to repeat itself now and then from blog-reading enquirers.
There are older posts that I've written in detail as to the Roman Catholic Church's institutes on the eremitic life--briefly stated in 920-921 of The Cathechism of the Catholic Church and further addition in the briefly stated CL 603.
However, I view the questions of "Can I become a Catholic hermit?" or "How can I become a Catholic hermit?" and of similar wording and intent, to remind me of recently coming upon yet another recently formed hermit "community".
This one is under the direction of a diocese bishop, and there are a listing of requirements for one to enter their community. I assume it is quite small for the location is given, and the entire town which would include the community has about 80 inhabitants, and judging by demographic information of population, the hermit community would be easily under ten, maybe way under.
Numbers do not matter, of course, especially in a hermit community. It could be rather odd to have formed a hermit community, to begin with, as a type of hermit religious order--thinly veiled by using Church lingo to ascribe to it another strata within the Consecrated Life of the Church designations.
Within their requirements are also descriptions of which they provide instruction in their efforts, on how to become a hermit. There are time requirements, as well. One has six months to a year to get the feel of it in their midst, and while getting that feel of hermit life (according to their or someone's interpretation of how a hermit lives and has "being") they can spend an occasional day in an actual hermitage. (And the hermitage they offer is no doubt according to how someone else thought it should be, also.)
Then there is a three-year period to learn more how to be a hermit but still live with a group of others learning to how to become a hermit with a little more time away to try out a hermitage for a day or two or so now and then. And then there are a few more years to learn more about how to be a hermit, and then profession of final vows in the hands of the bishop to be a publicly professed hermit under CL 603 provisions.
I find it all well thought-out and the requirements specific and detailed enough to keep those who would be allowed in to a minimum within age range, marital status, health, financial standing, belief system, few to no responsibility ties to the secular world, etc. All that just seemed like the regulations of any religious order, but groups do need guidelines, I suppose. Structure.
Any one individual's life does well with some structure! Any creature or plant life or creation of any kind exists within some structure, day-to-day and night-by-night.
Thus a hermit's life would be no exception in the matter of some structure. But what seems to me regarding if one can become a Catholic hermit or how one becomes a Catholic hermit--is that there does not need to be a joining of a community that is set up as if to teach someone how to become a hermit.
Yet, I suppose, if one has not confidence (or what can also be foolhardy in overconfidence) in the Lord and has no spiritual advisor or director nor books extant to read on the topic by spiritual masters and also by late hermits experienced from hermit lifetimes and guiding souls--and if one meets the rather lengthy list of requirements and wishes to be considered for a community to teach you how to become a hermit...give it a try.
The community I learned about is not quite the same as a lara--a group of hermits who live in a general vicinity in their own hermitages but are not in essence a quasi-religious order of hermits being taught to be nuns and monks much like postulants and novices in monasteries.
But to me, it seems sensible to pray and ask the Holy Spirit for guidance, and to ask Jesus to teach, and to ask Mary as the Queen of Hermits to assist, and even ask a priest or spiritual mentor to be a contact and advisor in the process as you discern and begin to live out either gradually or by jumping in feet first to living out the basics of hermit life in essence and substance offered in writing in the institutes of the Church and CL603 aforementioned above.
In ten days I will be celebrating 16 years since profession of my vows and priest approval of my Rule of Life (am not a CL 603 hermit), and of learning how to become and be a Catholic hermit, privately professed yet within the Consecrated Life of the Church. I'm very much a novice yet as just recently the Lord has shown yet another phase now of prayer, study, contemplation, praise, and always new and challenging penances.
It seems to me, that the Lord continues to be the best at unfolding a vocation such as a hermit vocation. Consider the very nature of eremites and the long history going back into the ages of the prophets and prior to them. Hermits have been, are, and will be. Regularization of hermit existence or attempting to develop a standardized type of essentially a boarding school for hermits with the idea of graduating them after a certain number of years into hermitages that are pre-conceived by someone else, some other hermit, to me seems contrived.
That may not be nice for me to comment upon or offer my thoughts regarding such, but I can at least attest that my various hermit life experiences have been rich and holy as well as painfully instructive, when I've let the Lord unfold all details of temporal and spiritual elements in my hermit vocation. I could no more tell someone else how they ought to have their hermit vocation formed and lived out, and less so to attempt to regularize the eremitic journey any more than I could choose the genetic make-up of a baby yet to be conceived.
Did John the Baptist go to a community of hermits? No, or perhaps it would be called a prophet community--but his life and soul were in that of what we would conclude an eremitic vocation--in solitude, out in the desert, living simply, communing with God, learning his mission, eventually some following after him to hear what he had to share of God's imparted wisdom and his take on living from what God had taught him in solitude amidst silence and suffering. Prayer, penance, praise--and then to proclaim the coming of the Messiah, Jesus the Christ!
I suppose all us Christians in some shape or format and in some place and time, have that mission. We are to proclaim Christ in some manner, visible or not, audible or not, temporally acknowledged or not, lived as seen or not.
Seems a simple prayer asking Jesus to guide our first and ensuing steps, bit by bit or sometimes in leaps and bounds, is a good start in becoming a hermit--or anything, any vocation, for that matter. If He leads you to something such as a community that is designed to teach you how to become a hermit and to remain with them as a hermit, and you fit the various requirements, then that is an option for you.
Probably, though, if one prays and waits and listens and reads and talks matters over with trusted spiritual mentor or priest or in the quiet of your inner Tabernacle in which Jesus is always present to you and for you, by and by--sometimes quickly--events and nudges will occur, and you will realize that you are becoming a Catholic hermit and are living the hermit life with it unfolding over time which can seem like an eternity or not.
God bless His Real Presence in you! Oh, and if the Lord leads you to a bishop and to seeking canonical approval as a hermit, that is good, too. Or if the Lord prefers to keep you more to Himself, that is good, as well. In this latter instance, you will not be approved in the eyes of people in your diocese nor be sanctioned by your bishop, but it is all right if you are or if you are not.
My instinct and unfolding path has been that the Lord's will is what matters most; and that could perhaps include His willing you to be in a community of hermits to learn how to be a hermit. Some people do maybe need more regularization or feel more secure with more temporally provided structure than do others; and structure can perhaps seem more time-efficient or results-oriented effective than the seeming unknowns of the solus Deus and faith alone journeyings of the more pilgrim-type or John-the-Baptist type eremites.
Mercy, this latter way can be dotted with scrapes and falls and missed-turns, revised do-overs, and try-agains in newly visible pathways. This latter has been the Lord's will for me, and it can be harrowing, lonely at times, but also touched by unexpected graces. I may yet be in my novitiate, for example, after nearly 16 years since vows! With Jesus as Teacher and Guide, we really don't have time or term limits.
I do know that in the third century or even among prophets, sometimes those who felt called by God would go to a seasoned hermit or prophet, and observe, ask questions, and live in a nearby hut or be kind of like an understudy, but that was not frequent. I think of Elijah with Elisha; but the Lord sent Elisha or provided him to take over from Elijah of whom the Lord was ready to take unto Himself and bodily remove out of this world.
I really know of few specifics of desert fathers with understudies or at least if so, not for long. The hermits might touch base with one another on rare occasion, or not. Usually for one desiring to be a hermit and finding a desert father or mother who would be willing to give counsel, was just a question or so, a day of observing or being taught some great truth through a spiritual riddle. Then off would go the more recently called-by-God hermit to build his hut or find a cave and start learning from the Holy Spirit and his angel, from Jesus and the Father, from the maternal protection of Mary: how to be a religious solitary, a hermit, an eremite.
But honestly, if you give the hermit life a try and a start, be assured that if it is not the Lord's will, He will also make that clear over time or in definite ways and means more quickly. The Lord often uses life events and others to help us discern, but there is nothing like taking the steps one learns from various means of prayer and research and trial by error, to find out if one is called and how to be a hermit.