Cynthia, I spent my lifetime "fixing" stuff. In fact, 40 years for a large chemical company doing that very thing, though in my case, it was turbines and pumps and compressors and other very large equipment. When you start to get into something like that, you begin to realize that there has always been someone who was capable of repairing it in the past, so why not you? It's always an enormous help to know how something actually works before you make a repair, but once you have that understanding, it makes a repair much easier.
Now that I'm retired, I like to call on that past knowledge to do things like install pickup systems in a guitar or setting neck relief. Obviously, the correct tools help enormously. There really aren't many repairs you can't do yourself with a little ingenuity and the aid of a YouTube video if you don't have a manual. It seems here lately I've done washer repairs, dryer repairs, dishwasher repairs and plumbing, all with the help of YouTube videos. At work we had manuals for everything, when we don't, many times you can find an online manual, or resort to YouTube, which I've done many times. You can repair just about anything you set your mind to.
West