There are many kinds of keyboard layouts (I have never seen a QWERTZ one though).
Here for example is the one I use:
I think the best thing you can do is to experiment.
For example Cmd+Y is for showing or hiding the preview – very commonly used.
See if Z works like Y on your keyboard (where is Y on a QWERTZ?).
I know for example that > on my keyboard should be held down for moving patterns manually.
The standard US/UK keyboard uses the tilde key for this (which I haven’t got except by holding down lots of keys together to make a tilde).
I'm using a QWERTZ layout (standard German layout).
Simply said: a lot of shortcut keys of US (or English) software versions are unusable in this layout. This doesn't concern shortcuts like Cmd + Y or Cmd + Q (you could change those anyway if you deserve so). But shortcuts for manipulating the shapes when creating a star or spiral and stuff like that can't be changed.