Could you edit your post and add your system specs? Instructions on how to do so here - https://answers.ea.com/t5/The-Sims-Mac/READ-FIRST-Sims-4-Mac-Help-Guides-and-Troubleshooting/m-p/4612396/highlight/true#M162 Also, if you could tell me what resolution you have in the settings and confirm that you are now playing in full screen mode?
So happy to hear that you are able to enjoy SimCity now. Happy Building!