B4X Starting over

I have no training in programming, coding. I just use my common sense and the crystal clear tutorials.
In about 2012 I once made a game in B4A and placed it in Google Play.
Now i resumed programming in 2021. Much is new and that takes some getting used to ...
It is now really B4X.
How beautiful it is. You program in B4J. Run and test in Windows until you are satisfied.
Than you already have your Windows app.
You only have to adjust the screens in B4A. In Android you have to deal with many different layouts.
You then have a Windows app and an Android app (and also an i-pad and some devices, if you want).
B4X. For me as a newcomer, the many old information was confusing. But now I have everything in order.
Still a persistent problem:
In B4J FileChooser works <use: B4XPages.GetNativeParent(Me)> but FileDialogs does not work.
In B4A FileDialogs works but FileChooser does not work.
Not even with the right libraries.
I solved this by creating a <Sub Filemanager> in B4J and B4A.
In B4J i put the FileChooser and in B4A the FileDialogs. I then use Public variables for FileName, FileDir and so on.
Then you don't have to adjust much. It works well, but there may be a better solution.
In any case, B4X is a wonderful piece of work.
For any beginner, download the Booklets Instructions and study them carefully.