I've been involved in my parish's RCIA program for well over a year now, in an attempt to learn more about my children's Catholic education (they attend the parish school). I feel I've come to a good place in my inquiry and would like to be baptised in the faith. (I was never baptised as an infant in any church). However, our deacon mentioned something just last week about my "state of marriage" and that it might affect my ability to join the church. I am currently living with my boyfriend and we have a child together; he is Catholic by upbringing if not in practice, but he does not, at this time, believe in marriage. Will his inability to take a legal step in our relationship prevent me from pursuing the Catholic faith to its fullest?
If you are an ongoing situation that places you objectively in state of mortal sin you cannot confess and receive absolution, or receive any of the other sacraments, unless and until you remedy that situation. That means leaving a cohabitation situation, convalidating a civil marriage, whatever it takes. So, yes your situation would prevent you from pursuing the Catholic faith. Just as a side note, you child has nothing to do with it. You could become Catholic if you no longer lived with your boyfriend and ceased sexual relations.