Fortunately I learned early on about working with cars. The smallest job will take a lot longer than you think and you always need a new tool. Screws and bolts are also a huge challenge in that they are difficult to reach or rusted solid.
With practice and the right tools things like oil changes, tire changes, (some mods...) and brake jobs are manageable.
Larger projects leave to the pros as they have the experience and tools.
This.
Any simple job can be literally made almost impossible by a simple screw that can't be unscrewed. You need a special tool, and even then you may not be strong enough to loosen it. I had to buy an impact driver for one stupid screw. The Youtube videos are highly misleading. There may be 8 simple steps, but each one may take hours the first time you try it. Also, being very weak, I learned just how much strength is required.
Also, how easy it is to break things and cause so much damage.
Even the simplest thing such as changing the wiper blade was a HUGE ordeal. Getting them off was almost impossible to begin with. It required a lot of tugging and pulling, and I wasn't sure I was pulling the right way. Then, the wipers I bought were impossbible to put on. Spent hours trying to find the right attachments and setup. Turns out they weren't the right ones. Then, it's easy to accidentally let go of the wiper blade and have it crashing onto the windshield. Happened to me twice. First time was over $1,000 to fix.
Changing the tires is incredibly difficult. My tire lugnuts would not come off no matter what. Finally bought a breaker bar which did the trick.
Then swapping tires is so much work and effort. My winter tires on steel rims are very heavy. Jacking up the car with scissor jacks was very hard. Also kind of dangerous.
My greatest fear is dying while working under a car that is jacked up. I'm absolutely certain that it would happen to me. That's why I only use rhino ramps.