There are several ways to edit digitized videos and films yourself.
For cutting and pasting only, I recommend LosslessCut.The advantage of this program is that the video does not need to be re-encoded and thus no quality is lost. If you want more, such as adding titles, music, transitions, etc. then you need a somewhat more comprehensive program. See here for my top five recommended free video editing programs:
Bewerken van video bestanden
If you have even more requirements, then a paid program is recommended. Some examples: Final cut pro (Apple) and Adobe Premiere / Magix Video for the PC.