Creeps can go choke on their own nastiness.

I’m 14. Whenever I walk down the street, old guys stare at me from their cars and it’s super disgusting. How do I learn to ignore this?

You don’t learn to ignore this.

You get help from others if you need it and return awkward to sender. You educate your friends and colleagues that this behavior is never okay. You get the police involved and let the perpetrators explain themselves to the authorities. If you can obtain their home addresses and places of employment, you send a text, e-mail, or letter to their spouses and bosses letting them know this is behavior that these men engage in. You get in contact with other girls and women that suffer this harassment and come up with strategies on how to report the offenders’ behavior.

You remind yourself that you’re never to blame for other people’s creepy behavior. Only creeps are responsible for their creepiness.  To hell with them.