Can I be friends with kids and teenagers?
Why do you want to be friends with kids and teenagers?
I'm the same person when I was a teenager, and I want to be friends with people who will understand me.
Even though you may mentally feel like a youth, if there is a significant age difference between you and teenagers, you shouldn't socialize with them as many people will find it inappropriate. You should try to find people closer to you in age to socialize with.
Nobody is attracted to teenagers like that.
It is expected that you have friends  your own age once you are an adult.