Should I Buy a Motorcycle, Scooter, or Car?

Hi, I'm 18. I'm in my last year of HS. I was recently kicked out of my (already abusive) home. I'm connecting myself with services- I'm already employed with the City of SD and looking for more employment. I really want to get a car or a scooter or motorcycle or something. I have about 4K saved up, and I don't have expenses at the moment. I'm looking to resume work - but does anyone know the process of getting any of those?

I already have a CA driver's license, and have been driving a car for maybe 1.5 years?

I'm not sure what the next steps are. Do I need to get a credit card and start building credit? How much should I have saved up before I even think about buying a scooter or motorcycle?

I don't have a lot of belongings, they all fit in my regular school backpack.

I should mention I'm 5'1, so if I found a motorcycle I would need a short one I think.

I am college bound to Humboldt or a UC with a 4.07 gpa that is expected to rise.

Thank you sincerely!