How old do you have to be to go on a race circuit on a motorcycle?

I want to practice my motorcycle skills but I don't know how old you have to be? I'm also a little confused on the process. I'm saving up to get like a 90s honda road race bike to practice on it and maybe race but I don't want to have to get it and then have someone tell me I can't drive it because i'm too young I'm 14 and I don't have a permit. Oh and can someone give me some recommendations for good starter bikes I'd appreciate it alot

Added (1). Oh now I feel dumb haha well yes I live in north america specifically Tampa Florida

Not sure where you are in the world but in the UK I know 3 tracks that will let you do track days after been followed by an instructor to see if you can handle yourself.

You will need to be with an adult off course.