These were the hardest courses of my life.
That's all I know, I wish I had an easier answer. I happen to have lived there at the time. I was lucky in that regard for accidentally finding that course.
I found the book "Reverse Engineering for beginners" quite useful. Its a bit tedious but if your serious about it and go through it a bit it'll give you some solid practice.
Also, write, compile, and reverse own snippets of your code to get more intuition about how things work.
Finally work on a actual target, not something crazy like Photoshop or Word but at least something real to get the practical experience. It might be a bit of a grind but when you do manage to crack/hack whatever it is your trying on, its an euphoric feeling
There is definitely a “clicks” moment. It took me three weeks from zero to key generator. Absolutely time worth spending.
Fravia was also popular, this seems to be a mirror of his site https://www.darkridge.com/~jpr5/mirror/fravia.org/aca400.htm
Or atleast that's how I got started as a midschooler with infinite time. Also try playing around with Cheat Engine. Don't let it's name fool you, it's a very advanced debugger that's capable to do way more than make you a bullet sponge :)