International child custody?

my child's father lives in Mexico, he is not allowed in the US legally. He has asked us to come and visit. He will cover cost for pports, airfare and hotels. I may have to come to terms that the only way for him to be involved in her life is for us to go there. I cannot go blindly. I am looking for advice, stories, and information on how to accomplish this wisely. Anyone know if there is a safe neutral meeting place for these sort of situations? I am wondering if this is anything a lawyer will be to help me with as well. Funds are tight for this single mom, want to choose my resources wisely.