I'm a 13 year old guy. I notice at school most people are in some kind of relationship. I admit, I feel kind of....lonely....sometimes. When do people usually get a girlfriend?

I am a 13 year old guy, and occasionally i masturbate(of course), and I find that it's REALLY messy. I usually get my underpants on before ejaculation, but it's still EXTREMELY annoying and difficult to clean up. Any ideas?