@julia_n_okiedoki Hopefully you haven't permanently deleted your Sims 4 folder, since it has your saves and builds in it. Even if it's in the recycle bin, you can still get it back. But for testing purposes, what matters is that it's no longer in Documents\Electronic Arts.
Since you can't launch the game even without that folder present, then we do need more information about your system. The EA help article about running a dxdiag is very thorough, and you don't have to do any more than run the command, wait for it to finish, save the info, and attach it to a post here. It will include a report about free storage, if you're wondering whether that's the issue, as well as information about a whole host of other potential problems.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/