Autism

In my state, I had to take a written exam (mostly about the rules of the road; very easy if you study the driver's manual for your state) first. Then, I had to spend at least six hours working with a professional driving instructor. Then, I practiced with my dad every once in a while until the road test, which I failed miserably because I was tired to the point of delirium, then I took it again a couple months later and passed with flying colors. After that, there was a probationary period for a year or two during which there were limits on the hours I was allowed to drive and how many passengers I could have. And that was it.

Basically, you need to legally start the process yourself through your local Department of Motor Vehicles (or the local equivalent) by indicating somehow that you want a license. To actually learn how to drive, get a fully licensed, trusted adult to ride along with you in your car and tell you about how to drive, while you...well, drive, preferably in an empty parking lot.

You also need to learn how to pass the road test; it is a completely separate skill from actually driving. Get a list of the things you'll be tested on (check your government's website) and replicate the testing setup on your own. For example, my dad actually sourced some cones for me to practice the parallel parking section of the test.

Really, you just gotta get in that car and drive. Drive in areas without cars until the nervousness goes away. The responsibility shouldn't be underestimated, but at the same time... it's not rocket science. Talking to the driving instructor was a lot scarier than driving ever was.

Make sure your car is actually allowed to be used in the road test. In my state, the car had to have either a second break pedal or a handbrake. If your car doesn't meet your state's criteria, you could probably borrow a driving instructor's car (for a few), but the best way to do it is to borrow a friend's or relative's car that you can actually bring to the test.

One thing to know about cars is that you get a lot more acceleration and turning than you actually need for the most part. Except in rare circumstances [1], you only need to make small movements with the accelerator. The brake pedal is quite strong when new, but will lose its strength over time.

Also, driving on the freeway [2] is different to driving on a typical road. IMO it is terrifying the first couple of times, but it's a lot easier after exposure. The thing about freeways is that you are in continuous motion (assuming no traffic jams or accidents). You need to approximately match the average speed of the rest of traffic. Because you're all moving at nearly the same speed and direction, the challenge with freeway driving reduces to a problem of not tapping other cars. The problem is mostly solved by slow, deliberate, signalled movements relative to other cars. Keep in mind that you still have to watch for stuff that isn't moving with traffic, like animals or debris that fell off a vehicle.

Your vehicle has a blind spot by the back passenger doors. You'll have to check those areas by physically rotating your head.

Lastly, we need to talk about cars in general. Despite the fact that I actually kind of like to drive, I cannot just forget the negative environmental impact that cars (including mine) have on our world. Additionally, car-centric infrastructure in the US establishes an enormous cost of entry to public life in a society which already makes life difficult for the poor at every other possible level. Even with the amazing breakthroughs in safety we've made with cars, they are still one of the more dangerous methods of transport per capita. Put simply: cars are bad for humans and good for the people who sell them. If you can get by without driving a car, then not only is that fine, it is better than driving one at all. However, at least in countries that have backed the automobile over public transit, having a car predictably gives you an advantage over those who don't.

[1] There's an old state highway in my area with a few exits where you come off a residential street from a dead stop directly into a 50 mph zone, with absolutely zero on-ramp. You have to literally floor it, or you'll probably get hit from behind. It's super dangerous, but also super fun. This is unusual; you usually get a good amount of space to accelerate and match the speed of traffic before you merge onto a highway. Ask your driver friends about dangerous/stupidly designed intersections, and I'm sure they'll have lots of stories. Memorize them, because someday it'll be you taking those intersections.

[2] IMO driving on local highways (ones with traffic lights) is a lot closer to just an ordinary road.