I installed Clean Installer without the .NET framework 2 and when I try to install anything it just spits out strings of numbers and letters in the teleport folder. Could this be because I'm using a different .NET version? I read that it's unsupported by microsoft and I really don't want to use old and vulnerable software if I don't necessarily have to. Could it be something else? Does anybody have any tips?

That's most likely a lot, and usually how installing a lot happens. Have you tried going ingame after installing? The lot should transfer from the teleport folder to the LotCatalog folder (with a different name) once you go ingame. The Teleport folder with the long random name is just a temporary stage.

If you install lots with CC, the CC items usually get installed into the Downloads folder.

If you install sims, those files should either end up in the SavedSims folder or Downloads folder, depending on the setup.

(at least this is how it should be when everything is set up correctly).