Think about all the different events that were recorded on your video tape. There were likely separate events, like birthdays, graduations, school plays, vacations, holiday events, and more. Since video files are quite large, it only makes sense to separate out the different events into separate video clips of smaller size.
There are a variety of paid for video editing apps, and a few free open source apps. Probably the easiest free app to use is OpenShot Video Editor. There are others like Kdenlive, ShotCut, and others that can be tried, but OpenShot, in my opinion, is the simplest to use.
