The best way to learn something is to do it. I learned from building my own bike, piecing together parts here and there. Whenever I got stuck, I just searched on youtube and there was always an answer. I mean no offence to this site, but it's the best way to get an answer right away. It's very rare to find a problem that is totally unique to you. You can search and find almost anything you want here, or youtube or any where else online.
Fixing your own bike is an awesome experience. My bike is fixed on my terms and on my time. If I need my bike for tomorrow, I'll have it ready for tomorrow, not next week when it's convenient to the shop guys/gals (no offence to the pros).
If you're not completely comfortable of just relying of YT videos or asking questions here, you can always go check out your local bike co-op, and ask all the stupid questions you want and learn how to wrench of your own bike with somebody who know what they're doing.
Give it a try. Worst case scenario, you do the walk of shame of bringing in your bike. But at least you tried.