There is this guy in my class that I have a crush on, but I dont know if he likes me back!?

well for one if the guy likes you he will look at you but when you caught them they will look away a little bit shy in front of you and make you feel that you are special

Or kisses u

Well, just look at his body language. If he normally is nervous around you and often fiddles with things in his hsnds, then the signs are good. If you often catch him glancing at you during class and then looks away once you see. If you want to make a move, then flash a smile back.
Hope I helped.

just talk to him, be friends with him first. get to know him and show him that you're interested in him, too!and b ur self. You do not need to change.then If he love you he will love u By nature and not an artificial girl
best luck

Well do you know his friends? If they are all talking at one laughing at your crush and he blushes as you walk past then it's pretty likely
But it's not always true. Your crush may be really chill around his crushes so he might show any signs at all. (But usually they do)
Hope this helped

Sit behind him if scratches his hea. He is nervous that u are sitting behind him. Make sure he is starin. At u then look at the clock have a friend watching to see if he looks at the clock to

If a boy likes you he would always look at you and he would be nice to you kinda like my crush.

Well, if he is looking directly at your eyes, if he stares at you a lot, or if he laughs at all our jokes.