Double-tapping a part of the actual recorded track, or region, will bring up another menu with different options. Most are obvious (cut, copy, delete, rename, trim), but there are also the very useful Split and, for MIDI tracks, Edit.
If you want to copy a certain part of a region, or have a recording that is nearly right apart from one bit, then you can cut it in half using Split. Simply place the playhead where you want the break, tap Split, then drag the little scissors icon down to create two separate regions.
Edit is a little more complicated so we’ll cover that next.