Girls Only!!!!!!!!!!!

It doesn't exactly means he likes you, he might just be flirting with あなた または even trying to annoy you, because if he liked あなた he might not try to make it THAT obvious によって calling あなた baby ...At least thats what I think

That depends all on what your type is if he's it smile and say "hey". If he's not don't smile and simply say "hello" he is way bellow あなた don't smile don't do anything もっと見る then look at him with a look of something like 'can i help you?' if he is out of your league in a good way, congrats, smile flirtfully and say "~hi~".
Good luck even though あなた shouldn't need it.

I don't really think it means anything. A lot of guys tend to walk up to a girl and say "Hey, baby" in a joking matter, nothing as serious as liking her. I'm guessing that he was just simply saying hi in his own little way.

I don't think he 発言しました it because he likes あなた ..

It's either in a funny matter OR he's trying make another girl (most likely his ex) jealous.

Every 日 ランダム guys come up to me and say 'will あなた go out with me?' または 'your so beautiful' as a joke and it really annoys me. I think he was probably joking または he liked あなた before and he's trying to cover it up:)