Cut & Trim
Cut:
1. Choose the ‘Razor’ tool from the tool menu.
2. Click the part of the clip that you want to cut
3. (if you made a mistake press ‘cmd/ctrl + z’ to undo it.)
Trim:
1. Hover the cursor over the beginning or end of a clip
2. Click and drag the clip to make it shorter.
3. If you click and drag the clip longer, the frames you trimmed reappear again.