yeah, most things are pretty fixable if you're willing to spend some time and buy some tools. You just have to keep an eye out for situations where you need a real pro. Especially if it's some kind of electrical thing.
Do you replace your own car headlight bulbs? Replacing a wear part like a washer or clearing a screen in a plumbing connection isn't a job for professionals. It's a half a step up from doing your own dusting and vacuuming.