Don’t know if you like music but the local DIY music scene is a good place to meet people. Start by going to shows at The Roboto Project, it’s a cheap all ages venue in Garfield. Follow local bands you like there on social media. When they post about playing house shows, DM them to get the address, they’re usually around Oakland. That’s how you can get involved with young people and make friends, it’s what I did when I was your age.