As you have the interest in learning bike mechanics, which for touring is a very good thing, to know your bike well mechanically, I would suggest starting right away doing work on a bike and learning.
It's like anything, we learn bit by bit and always learn new things. Same with Spanish, get going on that as well.
Good luck and have fun.
Look into a bike co-op for getting hands on experience, some teaching and access to tools to really start to get your hands dirty.
Seconded. It's a lovely experience. Find someone who knows more than you and let them teach you, at a bike shop, co-op, etc. You can figure out how to do the vast majority of roadside repairs in a matter of a day or two.