I have a crush on a guy in our school. Well his so hot but bigger than me in 3 years. Once my friend brought her phone to school and we took a picture of him but he knew we took a picture of him! It was SO AWKWARD! The next day he was following me and my friend, he keeps staring at us. Whenever I look at him I find him looking at me directly into the eyes.

There's all sorts of 'likes.' He knew you took a picture and with little looks etc he knows you have a crush. Because he is older he might just be enjoying the crush and staring at you to see your reaction. He might be curious or even attracted, but doesn't dare get involved because of the age difference. He might be angry about the picture! Who knows?
You can't really use the word 'like' until you have had at least 3 or 4 conversations with someone. Try saying hi when passing by in the halls, instead of being all secretive. If nothing happens after several hi's, then you know he won't get involved with you.

I can't talk to him though cause our school is an islamic school and we can't talk to guys.. or we'll get punished

He most likely does, can you talk after school

No we can't talk after school cause teachers are everywhere :c

This was probably a difficult and confusing situation for him under Islam - a girl could get in trouble for even a glancing look at a boy. Taking his picture, wow, in some areas you could be in really serious trouble. I would stay away from him no matter what (even though you are in a school with boys and girls together). Chances are that you will never get together because he will go on to more school or work while you have 3 more years to go, so try to forget about him.

Given the situation I think your best bet is to forget about him. No point in getting you both in trouble and getting your heart mixed up with something that can't be.

If you determined that he does like you, given that you are in an Islamic school, what would that mean? You can't date or see or talk to him anyway, right? Seems like you should just let it go - if you can't talk, and can't date then it doesn't matter whether he likes you or not.

Where do you live? In an Islamic country or in the West?