@Stinalina You can install the game on an external drive - open Origin and go to Preferences > Installs & Saves and change the game library location to the external drive. You may encounter an issue with the drive not showing up, have a read here to resolve it
https://bluebellflora.com/2020/11/26/external-drive-not-showing-in-origin/Once the game is downloaded and installed on the drive you can safely delete the base game and Sims 4 Packs folder from your Applications folder.
You can also store your Sims 4 folder on the external drive. This is trickier and involves creating a symlink which not everyone is comfortable doing but is the only way to get the game to recognise the Sims 4 folder in any other location other than the Documents Folder -
https://bluebellflora.com/saving-your-sims-4-folder-to-an-external-drive/ 
