How to properly use tutorials to study java inside out?

Currently it feels as though I am stuck between two phases: the introductory java tutorials which go over very short one line examples of using variables, operators, references, object instantiation, etc.

The second phase is the 'clone tutorial' phase where the tutorial is simply a recorded implementation but does not discuss each line of code in detail, and usually uses a specific package.

Right now I want to supplement an Intro to algorithms course in java because outside of class I have not programmed much at all and it is causing issues in my preformance.

I have been trying to focus more on textbooks than youtube tutorials because of this such as tony gaddis starting out with java (6th edition)

Mainly I have just been rewriting the program and trying to add small tweaks, such as changing a type from int to char or other arguably nonsensical iterations. I tried to go on forums such as codecamp to ask questions about individual lines of code even if it's as simple as "what does this line do?/why does this exist?" but it's a bit empty.

It seems as though there is more space for general career/learning advice rather than a space where you can bring specific albeit trivial code and ask questions about it. Where could I go for that as well(since I wasn't sure about the "do my homework" rule in this sub