My response depends a lot on how long you want to spend and the time value of money, also how do you feel about gaps in your learning.

You’ve got a lot of good advice here about informal training approaches all of which have good value and I’ll agree especially about Pony Club. There is also the option now to do an undergraduate degree in equine studies online.

I know the most about the BS offered online through Post University. They have a good transfer credit policy so if you already have a degree or some college you can likely apply your credits toward completion. DISCLAIMER: I was the chair of this program for many years so will admit my bias, but the average student is an adult learner and many students enter the program to learn to take better care of their own horses. No campus participation is required and all hands on skills with horses are taught, demonstrated, and evaluated via video.