Regarding Hard-disk copy and Digital copy

[Iscah]

I went to the library, and the game requires the disc to start the application do i need delete the game and see if it lets me download it digitally?

Yes, you can only have one version installed at a time.

If this is purely in preparation for the PS5 then there's no need to do it yet. But it does mean you'll won't have to use the disc to run it.

You'll need to download the base game and all the patches again, so it'll take a while to install. Don't do it when you want to play soon.