Need help in regard to starting Freelance Copywriting

I’ve tried to get a part time job, with none available and I had heard that freelance copywriting wasn’t that difficult to begin, though I’ve no clue how. I was going to start on Fiverr, but I’m not sure how. I’m 16 and have an A in both English literature and Language GCSE, and an A* in Journalism. How can I begin?