Hi,
I just started with Krita and have only made a few pictures with it yet, so I still know very little about how it works.
I think it's irritatíng that I can scroll so far past the edge of my picture. Then I have like 2 cm of my canvas and the rest is the gray background. Can I stop that or is that preset? If I go to "Show canvas only" I still can scroll past the edge.

No, this is not possible.

Not sure, but maybe keys '1' and '2', which center/fit image to screen can solve irritation. And middle mouse wheel zoom/pan helps me too.

Also, Image→Canvas Size (Ctrl+Alt+C) helps to overcome some issues with gray border pressure

dobrokotov's comment is the way to go: just press 2 to recenter your document and zoom on it so it takes as much space as possible on the canvas.

Thank you all for answering so fast! (I actually didn't expect that and didn't check for answer until now. Sorry for my late reply.)

Dobrokotov tips did help a bit, but I draw on a surface and usually take off the type cover to draw.
But since TheraHedwig pointed out that it's impossible to make the background disappear completely, I guess I'll just have to learn to live and draw with it. I hope I'll become accustomed to it with time.

Still thank you all for trying to answer my question.