Girl/guy problems. I need help!?

Well first off, I think you a bit young to be "dating" if that's what you want to call it. And because of your age, there's a really big chance that he's not going to be "the one". So relax and if things don't pick up, then break up. It's not going to be the end of the world. And if he's been lying to you about something small about dating someone else, what bigger things is he lying to you about? I wouldn't stress about it too much, your still young and have a long time to worry about guys.