The cut tool lives in the toolbar. Drag across the waveform to select and trim a section. No extra credits required.
You'll find the cut tool as a button in the toolbar, separate from the individual tracks.
Click and drag across the waveform to select the range you want to cut, then apply the cut. The timestamps are shown along the track, so you can line your selection up to an exact point in the song.
No. The cut tool is included in your plan, with no extra cost per use.