I dropped out of school last year, my junior year at the beginning of second semester. I need 3 credits for my junior year and if I want to go back at the beginning of second semester for my senior year then I need the 3 credits from 1st semester. That would be a total of 6 credits. Can you tell me how I can get them in time to graduate?

You will talk to the counselor to see what classes you have to take, and when they can be taken, They will tell you when you can graduate. Of course your parents should be with you