There is a simple 2 step process to learn how to fix your belongings, namely cars and household appliances.
Pretty straightforward! So go ahead, grab that hammer and start breaking shit!
In all seriousness, fixing your own stuff is the best way to fully understand how things work.
This allows you to be able to treat your belongings better and to use them to their fullest potential.
Think of it this way, if you can fix something, the odds of you understanding how it works and how to use it increase.
After banging my head against the wall for 2 years while building out my van, I can fix everything inside of it with ease. Not only that, but now I have the knowledge to treat my belongings with the care they deserve making them last longer.
Another great point of fixing your own stuff is that you save money by not paying other people to do it.
Especially with car work, auto shops charge 100$-200$ per hour for mechanic time, and plenty of shops are shady about their hours. (and quality of work)
Now sometimes, a project needs a specialist to be able to accomplish the task at hand. So in this case, paying someone else to do it makes far more sense than attempting to fix it and screwing it up.
On a similar note, a tedious project could make sense to hire out. Or a project that is simple and mindless, like scraping the paint off of your shed before you paint it.
All in all, I have learned a tremendous amount from breaking things and fixing them. In reality, don’t break things on purpose because things will start to break on their own. Just use your belongings until stuff goes wrong.