Hey guys I need your advice with this one.

I recently got to know this cute girl at driving school (she comes with her friend) and something I would find her looking at me(I don't what's that verb called) and sometimes we even had little chats.

Today as I was passing by them after the lesson I thought saying a bye but didn't say it thinking since we don't know much about each other it would some weird if I just said hello.

So that's my dilemma, should I have said hello/bye or did I do the right thing?