Birth Contorl Should I Get It Or No

So I'm 19. I'll be 20 in a few months. I've been thinking about getting on birth control for awhile. Bc 1) my periods are really bad (like stay in bed and don't move bad) . 2) My period are irregular. 3) I'm currently dating someone and we  periodically have unprotected sex. I don't know which birth control or where to get it... any suggestions?