nasti_2137 Look for the Sims 4 folder in one of these locations:
C:\Users\your username\Documents
C:\Users\your username\OneDrive\Documents
If you've ever played the game on this computer, the folder has to exist somewhere, that is unless it's been deleted (by you or for some other reason).
In case you're not sure what to do with this folder, please either rename it or move to your desktop, so the game can spawn a new copy with no added content.
If that doesn't help, please provide a dxdiag. Hit Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the camera (Insert Media) icon included with the other formatting buttons.
Please also post a screenshot of the error you're seeing.