I would generally enjoy the identity of the name as it clearly means he likes you. The term 'babe' is mainly used in flirting so this could mean he is flirting with you. Depending on what else he has said, should identify you on how to answer back. I would try lightly flirting back to see his reaction.
The guys are just saying it in a flirty way, lol, just loosten up and flirt back with them saying like oh hey sugar, or, if you like them and you want them all over you, you should just be like oh hi. And make him do all the talking.
The guys are just saying hello
It Mean you r hot and pretty they love you
They could be joking or they like you .and its a different what of saying hey