I will agree with Neutrino

Converting to a religion, any religion, solely for its position on a single issue is rather shallow and likely to be disappointing. Every major religion takes on a variety of issues related to very different life aspects. You should carefully study it before. And of course, talk with others who are already walking the walk.

I will also agree that all religions old enough are at least indifferent to paedophilia. It really is a modern issue and historical anomaly.

As for the Muhammad-Aisha marriage, the story is as you know it. However, current Islam, for the most part[*], does not overtly try to subvert existing civil laws that contradict this precedent; and some Muslims actually try to rationalize or reinterpret the story in a politically correct way. Of course, on the other hand, some of the lowest ages of consent in the world are in sharia-based countries (Yemen, Gaza, Kuwait, Iran, Brunei), and that is due to this precedent (and to the comparatively low influence Western culture has had on them). Consider, though, that in Islam sex is only allowed within marriage and therefore you (and she) are still liable for adultery if you're not married to each other.

[*] Of course, in political Islamism, as in all revolutionary movements, there simultaneously coexist those who believe in reform while loyal, and those who believe in active disobedience of the law. So yes, some of political Islamism would agree with breaking an un-Islamic AOC.