EDIT: I just saw the files are already 480p digital format, I'm a moron and missed that in your original post. My reply has been revised:
Computer people please correct me, but I believe a GPU is primarily responsible for any video sent OUT to your monitor(s). Your processor handles any any mixing and editing of video files and 480p isn't nearly as bad as 1080p and 4k. However, I have no idea if upscaling(?) to larger, higher resolution formats is beneficial (I seem to recall there is a benefit but please verify), and that is the first thing I would google. Plenty of people have old 480p vids that they want to mix, master, and edit for modern use and they have posted the most optimal solutions. Lately I have been skipping google and just searching on youtube for these matters.
If you will be editing in a format larger than 480p, than you will need a reasonably robust processor AND ram. I wish I knew accurate specifications, but I guarantee a quick google search should solve that, something like "computer specs for editing 1080p video (or 4k)."
The best advice I can give is to take a night (or a week or a month if you have to) and thoroughly research this process. Watch as many videos as you can until you know for sure what you want to do, that way you don't process 100's of hours of video only to discover there was a better method or something.