You are not old. I think get the “priesthood” out of the way i.e. consider it, pray about it and see if you are called to the “priesthood”. I say this because the older you are, the more difficult it would be to get accepted into seminary - whereas marriage would be comparatively easier.
If you have a vocation to the priesthood that thought would keep coming back to you even if you push it away. Hence, I suggest spending time in prayer. If you get the thought of becoming a priest, thank God about it, and ask him if he wants you to go there. You would probably feel that you get *no answer*. Then push the thought away – not because its bad, but because you cannot make anything of it.
I can assure you that if you have a vocation to the priesthood this thought would keep coming back. In all of this keep up your prayer life, so that the Lord could talk to you. If the thought does not come back to you, then you are called to marriage.
In all of this be very clear in your mind about the distinction between the “Call to Holiness” and the “Call to Holy Orders”. The first is universal, the second is not. Some people do not understand this distinction. St. Jerome for e.g. did not have a good opinion of marriage and thought that it should only be tolerated because it was a breeding ground of future celibates. This is not true. It is through marriage that most of us men find our priesthood.
AMS is for people like yourself i.e. faithful catholics who want to find a practicing spouse. I can assure you that you will not have any problem with transgender folks on AMS. Most if not all are devout Catholics who are eligible to marry in the Church (though some are Traditional SSPX).
I just joined AMS, and I don’t think there are many girls in your age range. (I am assuming you are a guy because in another thread you mentioned about problems with a female friend.) Once you get to 24 – 25 yrs, there are a lot more girls. Most AMS relationships are long distance i.e. you should be ready to drive for a few hours to find someone.
One thing to note is AMS is a one-time fee, so you might as well pay it now, and keep it for life (or up till you find a wife ) If you can afford it, join right away, otherwise join in the next two to three years.
I hope this helped you,