Autism

Unfortunately, the most helpful resource in my experience is having someone to show you how to do stuff. Failing that, youtube videos, trial and error, and taking apart existing clothes are all good ways to learn. I don't have a particular channel I go to; I usually just look up something like "how to sew a welt pocket" and then click on videos until I find something that helps.

As someone who's self-taught, knowing the right terms for things has been a big hurdle. List-type articles like "twelve different ways to sew a seam" was useful for identifying, say, a flat-felled seam versus a standard seam. There's a ton of jargon that's hard to remember at first, but the more you're exposed to and use it the more you'll remember. (Example: in programming, there's this concept called an "image." I don't know what it is, don't ask me. It's not a literal picture, apparently. In sewing, there's this thing called "bias" and I can easily explain that it's the diagonal of woven fabric.)

Sewing is made up of a ton of different "steps" (or maybe techniques?) but you don't actually need to know everything, and there are multiple ways to do everything. For example, if you're hand-sewing, you could knot the thread. Or...you could just leave a long tail and do a couple of backstitches, and apparently that's usually just as effective. Another example: to finish a hem (meaning preventing it from fraying) you can use pinking shears to cut it. Or you can cut the fabric so that the hem is on the bias. Or you can use bias tape to bind the hem. Or you can create a rolled hem. And so on.