It's a journey, and it never ends. After more than 50 years, I'm still learning, & so is everyone else that I know. Our horses teach us new things almost every day, and while it's great to read and watch videos, experience itself is the best teacher.
All beginner riders, and everyone who is serious about riding, should take lessons. If you don't know an instructor, ask horsemen in your area for recommendations. Ask at your vet clinic, ask your farrier, go to shows and ask the riders you admire. When I started taking lessons in 1981, a group lesson cost $25 per person. 31 years later, my instructor still offers group lessons at that same low price. Such a value! Prices of most other things have doubled, or quadrupled. And riding lessons are FUN, as well as helpful to your growth and development as a rider.
SAFETY FIRST! Always wear a helmet! Your brain is worth protecting! On Easter Sunday afternoon, 2006, I woke up in an emergency room with a concussion and 27 stitches in the back of my head. To this day, I don't remember how I managed to fall off of that very gentle, well-trained show horse ... but we missed the show we were planning to enter that next week, and as soon as I was able to drive, I bought myself a safety helmet.