I have some question about joining the Catholic Church I'm 14 and plan on joining the Catholic Church once I am a adult , I plan on studying the religion tell im am a adult to know if it's right for me , I was wondering if there was any reason a priest would tell me no I can't join or can anybody sign up RCIA , also wondering if there is a age limit to join
Not being a Roman Catholic I do not know all the answers.  However, I was in my late 20s when I considered joining the Catholic church because my fiancee was (and still is) Roman Catholic.  I did not go through with it (at the time) only because we ended up not getting married.  I am certain that the Pope right down to the local priest would be more than happy to have you join their flock, as would any denomination, regardless of age.   

As far as RCIA the only requirements that I am aware of is that you are presently not Roman Catholic, and you are above the age of infant baptism.