Should I become a nurse practitioner or a doctor?

It is not the same amount of school. Becoming an NP requires a BSN, then a 2-3 year program for the NP training. You typically have to work as a nurse in between for a few years before admitting to an NP training program. A doctor does an undergraduate degree, then goes to 4 years of med school, then does a residency of 3-6 years.

Both medicine and nursing are competitive programs to get into. For most nursing programs, you will be admitted to the university to start pre-reqs but you will apply separately for the nursing program, usually after completing some of your basic sciences. You will need a high GPA as admission to nursing programs is competitive.

To get into med school, you will need to complete your undergraduate degree and all the necessary prerequisites with a very high GPA and also show a great MCAT score and a well-rounded resume of activities. The competition is very intense and less than half of med school applicants get a place in medical school. (At some specific schools the acceptance rate is less than 5%.) Keep these things in mind as you decide which career to pursue.

Make sure that you read and research both fields to understand what the differences are. Good luck.

First of all, it is not the same amount of time to become a doctor. It is the same amount of time as getting a master's degree, it's easier than becoming a doctor, and you don't have to do a specialty residency.

Frankly, your grades at this stage aren't high enough to make you competitive in either field. You would have to raise your GPA to a 3.8-4.0 in college in order to have a chance at either program.