If you want to fly your drone for purposes under than a hobby, such as for
profit, then you will have to acquire the FAA part 107 Drone License if you want to
legally make a profit. First off, you must be at least 16 years and be a US citizen
with no health conditions that can impair your flight. The main obstacle to getting the
license is taking the test which consists of a 60 question multiple choice test with 2 hours to take it. For studying, you can refer to this link https://northrup.photo/free-faa-part-107-suas-drone-certification-study-guide/.
For studying, I highly recommend this course from Drone Launch Academy
You can register for the test through CATS testing and after doing so, will have to pay $160 or $150 if you are already registered with the FAA. After passing the test, you
then have to follow the instructions given to you. You should get a temporary certificate 1-2 weeks after the test and your full license 4-6 weeks after.
Good luck on you getting your drone license!