OK. Then you need software to enable ripping the DVD's, editing the ripped files, and creating a new DVD. That may mean 2 or 3 pieces of software. One or two for dealing with the ripping and burning of the DVD's, and one for editing the ripped files. I'd suggest HANDBRAKE (lots of YouTube How to's) to rip your DVD's and IMGBURN to create your new DVD. Both programs are free. Now all you need to do is select an editor. Maybe all you need is Windows Movie Maker, but the list provided by bilvihur looks interesting, particularly the top rated item by Blackmagic. That's a well respected video company.
I was always taught to honor my elders, but it's getting harder and harder to find any.