well i messaged this girl on facebook saying "hey maria" shes 2 years younger, but im guessing she thinks shes all that, soooo i see her in school should i introduce my self or should i try another message on facebook? and she didnt respond to mine

She goes to your school and you're messaging her on facebook with something like that when you've never spoken to her in person.

Alright I want you to think about that for a second... has it clicked yet? I really hope we don't have to explain what you just did wrong there. But ok...

No, she doesn't think she's "all that". You messaged her saying hey, that's it. What is she supposed to do, just say hey back? Who even does that? When you message someone on facebook you do it with a purpose, to ask a question. So that's mistake #1.

Mistake #2 is that she doesn't even know you and the fact that you've chosen this medium to contact her when she goes to your school sends off really weird vibes. Congratulations, you are now the weird facebook guy.

Look I'm new and don't really know what I'm doing. I'm 24 however.

Why don't you approach her with her friends and say like hi you're cool but what's with this girl right there, is she like maid mary or something ? I mean she looks good but doesn't seem to know how to express herself.

Or whatever neg.

I mean why are you contacting her on facebook. That doesn't make sense if you can reach her IRL.

You don't care to contact her twice IMO especially if you would know she was able to reply but didn't. And what's with the opener, it's lke nothing. It's like the least special you could be. Doesn't say anything other than you giving an IOI. Which isn't really good. You need to do an indirect approach but in real life.