@Takiro’s suggestion is the simplest method and the easiest to undersŧand as well as being flexible.
If you want to do that sort of thing often and in a repeatable way, you can make .kra files that ‘operate’ on images to scale and move them in various ways.
I did a simple picture grid arrangement using that technique and it could be adapted for a variety of arrangements.
Here is an explanation topic with a download link for some template .kra files:
However, if you’re a beginner with krita and with image processing applications, I would not be able to explain it to you because it uses a variety of techniques and tools, each of which is quite complicated.
By all means try it but don’t be surprised if it seems confusing.