I kinda like this guy, but the problem is, I think I'm too old for him, and imma little confuse Help :(?

At 12 turning 13 he is still quite immature, even if he's a mature 13 year old. I think it's great for you 2 to be friends but I wouldn't let it turn into anything more than that. You are 15 girly so you are going to meet plenty more guys and some will be more suited to you. I know you have these really strong feelings for him, but you're going to have the chance to have feelings for plenty more guys that are your age. Somebody as young as this guy however doesn't really quite know yet what he is looking for in a girly, so it's best to save yourself the hurt and choose not to date him.