Several approaches
Remove unwanted segments from the timeline...
Import the clip, then drag it to the timeline, or right-click|PLACE ON TIMELINE. Then place splits at the start and points of material that will be deleted. Right-click on the new 'to be deleted' clip and DELETE|RIPPLE. It will vanish, and the clips to its right will slide left, leaving no gap.
Add desired segments to the timeline...
Import the clip, but do not place it on the timeline. Click on the clip in the bin. Then, under the preview window drag the scrubber (red line) to the IN point that you want. Click [SET START. Drag it to where you want video to end and ]SET END. Click the chevron at the right of the ADD button and choose where the clip is to be placed. It appears on the timeline at that position.
This can be repeated time after time. First click the clip in the bin, then mark new points. If you prefer to have individual clips in the bin that reflect each sub-clip, first duplicate the original by right-clicking on it and COPYing. Then right-click and PASTE CLIP. Any number of duplicates can be added.
Check out tutorials at https://www.nchsoftware.com/videopad/tutorial.html