hi guys,this will probably be hard for me to explain it to you the way i want because english is not my first language,but i think i will do ok:)
ok,so there is this girl in my highschool,i like it a lot,even my friends say that si is not that beautiful,just nice,anyway i see her perfect(hard to explain)so,everytime i see her,anywhere (our clases shared the same room for one hour this week)she looks at me until i try to look at her,that's when she is looking away,i dont know why,if i don't turn my head she keeps watching me...any advice?is hard for me to open just for the reason because i like her(strange right?)

sorry for my bad language,i hope you guys understand what i tried to tell you.

Pretty strong IOI she's giving (as long as you're not exagurating), work on your inner game, go to clubs fuck other girls get over her. Come back, do very little or SKIP A2 entirely, textbook game from there.

belive me,i'm not,the bad part is that my time to do that is running ,is my last year in high,if i could just come back after 1 year of college
what i don't undestand is why she doesn't keeps visual contact,like she whould be scared of me )

She doesn't keep eye-contact with you purely because she's embarrased or shy. You say your friends don't think much of her, yet you think she's 'perfect', therefore she probably isn't used to getting attention. I doubt she has much self confidence.

If you like her as much as you say you do, do something about it. Trust me, when you get talking to her she will want to make the conversation flow as much as you do by the sounds of it.

i am just afraid that being shy or not very confident,that she could think i aproached her just like a joke...i hope she wouldn't )

No mate, she wouldn't. You might get that impression if she is shy, but deep down she will appreciate the fact you approached her regardless of the outcome. But from what you've said, I promise you have nothing to lose!

tx mate,one last question,should i play by the book,or just go and say hi and let de conversation come naturaly?

I don't see the need for you to play anything by the book here. She's a shy, quiet girl, therefore I believe you should just be yourself and let it flow naturally.

Just have in your head how you're going to open it, and have a few topics of conversation you can speak to her about should the conversation seem to be dying or if it seems a little awkward.

Be yourself, act genuine and she'll be flattered with the attention!