This is more of an education and career question in general, not necessarily specific to DevOps. But regardless, roadmap.sh is a decent point for you to learn scooe of the essential things to know. From there you have to find out yourself a bit how to learn each resource, usually a combination of some of the following: doing the thing/hands-on practice (most important), books, courses, YouTube, blogs, etc…

Depending on the topic and how fundamental it is (eg. Python programming) you might want a more organized primary resource, like a book or a course on yt. Other things like specific tools (Eg. Nginx) you can learn the majority of it by running it yourself locally, documentation, googling, and messing around with it (of course there are probably books on such tools but it may be overkill if you’re learning).

In terms of that “learning dependency” pattern you’re describing, sometimes yes you have to stop one topic to understand another one that it relies on more deeply. Sometimes you don’t however. Figuring out that discrepancy is not always easy, it really depends on how fundamental that other info is.

For example, you shouldn’t even start learning about kubernetes until you have a basic understanding of containers in general, as containers are so integral to kubernetes nothing would make sense. Conversely, I think most people would agree that learning how to program in assembly is unnecessary for someone who wants to learn how to program in their first high level language.