I was married out side of the Catholic Church to a non Catholic at age 18. We divorced after his countless affairs with other women. I have been single for over 15 years and would like to know if I met the person God has for me, would I be allowed to marry in the Catholic Church.
Your prior marriage must be declared null before you will be allowed to attempt marriage in the Church.
If you were a Catholic when you married and you did not get formal permission to marry outside the Church then your marriage was likely invalid due to failure to observe the required canonical form of marriage. In such a case the annulment process should be relatively quick and simple. (See The Documentary Process.)
If you were not a Catholic when you married then you were not required to observe the canonical form of marriage so your marriage cannot be declared null on that basis. Another nullifying factor must be established before such a marriage can be declared null.
Consult your pastor for more information.