In LA, my situation was mostly playing video games at friends’ homes after school. I’ve taken buses since I was in middle school, though, and had a key to my home. That said, my dad is and was an abusive alcoholic, so I generally stayed out as long as possible.
Mind you, how unsafe the city is isn’t really true in many neighborhoods, especially if you’re with other teens. You can always hang out at various locations like malls, parks, the beach, library or at school. You have a lot of options in the city, especially if you’re willing to take a bus or bike places. I had friends who volunteered for Heal the Bay, for instance.