Before we get started, here are some resources you might find useful. Feel free to download them now, or rest assured you can always come back to check them out later!
Course slides (click the link to access via Google Slides)
Printable "cheat sheet" of MuseScore 3 keyboard shortcuts in Letter and A4 formats.
Here is a German version of the shortcuts, it may be somewhat out of date but should still be useful: