How 2 handel your first car?

I am a 15 year old female who's turning 16 very shortly & im going to learn how 2 drive around May. What do u think I should do Buy the car cash & just pay for it every month? Also do u have 2 pay for both car margrade & car insurrance? Im not going to get it now but I just want to prepair for it. Also What other way can I get a car without paying for it in cash? Aslo mom cant do it for me because she has bad credit. If i have good credit can I cole sign for it myself