Remember that you can't learn _everything_ at once. You have to choose a focus. That could be a tool you want to exist, a hero you want to emulate, or a problem you want to solve. There's a section in Mastering Software Technique that discusses this: https://software-technique.com/ (it is a book, but one that I highly recommend for people wanting to learn software development better). Ultimately, that focus can shift over time as needed, and the most important thing about it is that it motivates you.
For me, I mostly manage self-study via projects. There are various things I'd like to build. Lately, I've been using Nim to build various tools I'd like to have, which has involved learning about different facets of Nim, and it's libraries.
For me, if what I want to learn is less concrete, having a personal wiki also helps. I currently use VimWiki at work to track what I need to write down, but anything that makes it easy to link between articles, and doesn't put too much of an editing barrier up is good.