Ahhh here we go. You helped a ton with your question. 9 times out if 10 you should use the OS repositories to install packages/software. AKA the linux version of app stores.

You are doing it the old school windows way. That is to say you're going out to the internet and manually downloading software/Deb packages. If you're unsure of what your doing that way will likely end up with a broken system.

Let's start here, do you have an Intel, amd or Nvidia card? Mesa are the open source drivers for 3d graphics. So I imagine you were working on that when you left off.