Codex is excellent and fun way to learn many different coding skills, they have a good amount of content for free as well more for $15/month. I would definately recommend the memebership if you can afford it, I have found it to be very helpful.
Typing Club teaches you touch typing if, like me, you never learned.
Archive.org has extensive archives of various forms of content. Most people have heard of it, i think, but im still adding it just in case.
Alternate to, shows alternatives to paid software.
Goblin tools has a variety of AI productivity tools, I use to it to break down tasks into smaller steps so it feels less overwhelming.
Wolfram Alpha is the best search engine/AI for math/stem topics imo.