Dunno...try a dildo first.
Or maybe get one of those male sex dolls and start with that.
If you can tolerate (is that a good word here...tolerate?) that situation, then you can probably handle having a real dick in your mouth.
If you decide you don't like it after that, then you can say no harm no foul, because at this point, you technically still wouldn't have sucked an ACTUAL dick.
If you get with a guy, even a handsome, big dick one, as you specifically put it, and halfway through the act you come to realize that this sucks for you (no pun intended) then it could be an awkward moment. Dude might want you to finish, and you're like, I don't want to finish....could get a little dicey there.