Learn programming by heart?

I'm currently watching videos about programming plugins for Minecraft.

However, until now I have only watched the script quazi.

But I want to be able to "memorize" the programming.

Can you give me tips there, or does it come by itself?

This is particularly important in long-term memory if you practically repeat it yourself.
So, for example, if you are watching a video that is about programming a plugin for organizing player ranks, you first have a full look at it and then go back to the beginning of the video. Then you always stop as far as you came and write the same code in your program yourself. When you are done with everything, you really try to understand everything, including why you are doing it that way and not in any other way. If you can do most of the code then you can start with the next program and will make familiarity similar codes, which widens your horizon more and more.

Then disassemble Dan code, see what each command does and see what else you can do with it.

Then start by learning the basics of Java. You can deal with Minecraft later. You get to know the APIs there through a lot of research in the documentation and through practical application.

To solve problems independently, it takes practice to formulate and analyze them. Problems can be broken down into sub-problems that are easier to solve, for example.