It is totally normal to be afraid of a relationship because you feel you are inexperienced.  You are 13.  People grow differently.  You don't need to feel you aren't as mature or cool or attractive because you aren't keeping up with people who are growing up too fast. 

I was just like you at 13 I was interested in guys but did not want to feel pressured to do anything that I wasn't ready for.  I hung out with older people because it seems by the time people are 16 or 17 they don't care what you've done or who you've done it with.  Don't rush into anything and if you find yourself falling for somebody, dictate the pace and don't let it change your morals or standards.