Can't play in fullscreen and other issues

fi4qhliqmo45​  I've split your post into its own thread because you have a few different isseus, some of which are definitely not related to the DirectX 11 version of Sims 4.

The inability to load into any household is often mod-related, so please remove your Mods folder and try again.  If that doesn't help, try playing in a clean user folder.  Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop.  When you launch the game, a clean folder will spawn with no content.  (Your saves and other content will be intact in the folder you've moved but temporarily unread by the game.)  Don't add anything to the new folder yet; just start a new save and see whether you can get into live mode.

For the inability to play in fullscreen mode, do you have another app, for example the Nvidia App or GeForce Experience, set to "optimize" your games?  If so, it could be imposing certain graphics settings and preventing you from changing them.

The unrecognized video card error can be ignored, but I can also help you fix it if you like.

Your dxdiag crashed multiple times while running, so it doesn't contain all the relevant information.  So I might need a new one, but you can hold off on that for now.