I’m autistic, I’ve had one haircut since covid because I hate the sensory aspect of haircuts. I’ve been searching online of how to cut hair and it doesn’t look that hard, but a lot of people seem to advise against it. I think that if I fuck it up it’s not the end of the world, I can just go to a professional. But I have very long hair so I have a lot of opportunity for trial and error. I think that if I get some practice, it’s something I can continue to do going forward. I also don’t particularly care how it looks, I just want it to be shorter.
I was a barber and yes, if your hair is long, you can trim it without training, as long as it’s not very straight it doesn’t matter if it’s precise. Short hair and straight hair are less forgiving.
Basically you just want to make sure the two sides left and right are the same length and there are no “points” - no sharp length changes.
I’d just look for videos with people who have hair similar to yours, showing how they cut their own hair. You can do it!