All my life i was never been able to progress past beginner level. When i read a book or study a game i can't long term memorize what i do or what i read. So in practice what do you do to progress ? Do you write notes to summarize your games or your readings ? Do you have a planning to refresh your learning ? For example How much time do you need to memorize a type of finale ?
How do you learn anything?
If it is not new then why did not not learn it when you saw it before?
World Champ Lasker said he did not memorize anything he could deduce.
So to more directly answer the question: You start with the very basics like set up the board and how things move. Then you add on that with new ideas and concepts. Then keep repeating until you have hit your maximum ability.
The issue seems to be that you have a learning problem at least with the way you do it which seems to be trying to memorize everything. You need to understand not memorize.
At your level the best way to progress is to read anything you can and understand it but do not memorize it. But it should be just a little bit more advanced than you are. Trying to read something too far advanced and you won't get any value from it.
After that initial basic learning , you would progress a lot by playing over GM games from a tournament. That will give you a feeling for good moves (or at least better moves than you would try on the average) and by repetition of openings the GMs use you will start to see how those openings are played and the type of positions they lead to.
Finally actually playing serious chess in tournaments will force you to use what you learned. Experience with losing should help you remember not to do certain types of moves in similar positions.
In summary you do not memorize anything. You understand it then do the work to apply it when you need to use it again in a new but similar position.
I am not sure what you mean by a finale but if that means end game then you study books on endgames. Fines BCE was the classic. There are newer ones now. Just learning the ideas of how to play a few basic endgames would raise your rating a lot. Many players do not know how to play end games at all.
When you advance far enough then you get past just knowing tactical motifs so you will start to learn positional ideas too.
But to get that far you do need to study the tactical basics near the beginning of your learning journey, so you can recognize them at a glance in a similar position. Good example is smothered mate. Almost everybody even beginners have learned that one once it has happened to them.
Final note: Random positions for tactics will not teach much. You need to find collections of similar positions that you can learn from. Ideally there may also be graded sections that build on the core basic idea but wrap it in more complex positions. But doing many similar ones will reinforce your ability to recognize similar ones in your games will be much more effective than doing random puzzles/tests on some web site.