"What do I do if I kind of think I like my best friend but I'm not sure/What do I tell him?"

This is tricky because if you do like him and you tell him things will change. It won't be a bad change it will just be different than what you have now.

The only way to tell if you like a guy is to picture yourself kissing them or something haha to see if it would be weird or not. Because chances are you're telling yourself you like him because he's your good friend and you don't like any other guys so he's an easy pick.

If you really do like him though, and he likes you back you will have an awesome relationship because you already know each other so well and you're such great friends.

Try not to over think things, but if you think you really truly like him then go ahead and tell him.

Good Luck!