Emacs

I'm a noob (of nearly 3 years using emacs).

Buffer / window management still confuses me.

I haven't really learned to use / position / switch windows and buffers. Simply because I used to one org-mode window most of the time.

Now I'm using org-roam, amd dealing with multiple small files, I keep getting stuck in silly situations, like ending up with:

• a roam buffer and my fallback buffer vertically stacked - when I want to "fullscreen" the window with the roam buffer, I can't delete or kill the fallback window / buffer.

• two fallback buffers vertically stacked. Neither of which I can kill or delete.

Is there a good guide somewhere?