Start with Making a living with Photography (16 min, Peter McKinnon), then HOW TO MAKE MONEY WITH PHOTOGRAPHY - Things I wish I knew (9 min, Peter McKinnon). All 165 lessons here are free, from the teachers' own official uploads. You'll need laptop stand, noise-cancelling headphones, second monitor and a few more basics (about $270 of kit). The book to keep beside you: The Freelancer's Bible by Sara Horowitz.