Penny5525 Please disable any apps you use that come with overlays: Discord, Steam, etc. Disable the EA App in-game overlay as well, under Settings > Application.
If that doesn't help, please tell the game to open in windowed mode. Go into Documents > Electronic Arts > The Sims 4, open Options.ini, and set fullscreen to 0 (zero).
If that doesn't help either, please provide a dxdiag. Click 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 paper clip (Attachment) icon included with the other formatting buttons.