• Text notes
    . Hit
    N
    to bring up the New note window and start writing!
  • Bookmarks
    . Hit
    B
    to bring up the link artifact window;
  • Images
    . Hit
    I
    to bring up the media file browser window;
Reminder:
you can always hit
Cmd V
/
Ctrl V
to paste the content from your clipboard.
Also hitting
C
opens up the Collect menu that you can navigate with keyboard.
Hope this is useful!
Best,
Igor