How to auto select new screen when moving pointer from one monitor to another?
This is one of those paradigm shifts that really irritates Windows users &amp; Mac users usually are just so used to it they either forget it happens, or prefer it because it's never 'dangerous' in that the first click can't accidentally trigger an action, it just foregrounds the app.
Of course, the other way round, Mac users are constantly clicking &amp; actioning things on Windows when all they wanted to do was simply foreground the app ;)

There is an override behaviour which you may be able to use on occasions, but I know of no way to permanently change what is core behaviour on macOS.

If you hold  Cmd ⌘  as you click in a backgrounded app, you should be able to act on a button or element without bringing the app to the front.
Of course, if you need more than a simple click action, you will have to foreground the app eventually.

On the upside, you never have to foreground an app to scroll a window; merely hovering the cursor over it is sufficient to focus the scroll action.