Bang on advice so far. If I may reiterate, being unable to fix something but at least knowing what is wrong can save you from being ripped off.
It's an old adage but, I trained to become a teacher but didn't learn how to teach until I had a class of teens sat in front of me.
I'd suggest the same. Buy a cheap second bike. Crashed, blown, whatever. Buy the relevant Haynes manual (gold), strip it, rebuild it, make mistakes, think about it, read the book, try again ....etc.
You'll learn loads, you'll enjoy it and maybe you might make a few quid on resale? I'd suggest it to be a better option than the classroom. Get some buddies on board and make it a social event! But be careful, you might end up in the shed every night instead of watching TV with the missus....
This way, you'll appreciate good tools, you'll start to build a nice collection that will probably last you for life rather than borrowing someone else's. I still have and use the same tools I had as an apprentice. You'll know your way around your toolbox rather than the ones hanging on the classroom wall. And riding a rebuilt machine for the first time is still an experience I cherish.
I'm not knocking the courses, they're great by all accounts, but for the purpose of roadside repairs and minor fettling, you can't beat experience and learning by mistakes is invaluable. You never forget them!