zrcjoljr45zz You've somehow downloaded the old 32-bit version of Sims 3, and even the installer won't run on your Mac because it's a 32-bit app, which your OS doesn't support. (I know this because the EA App only runs in versions of macOS that are too new to support 32-bit apps.)
This usually happens because someone doesn't have the "entitlements," as they're called, for the 64-bit version of the game and any packs they own. To get those entitlements, you'll need to contact EA customer support. I would strongly suggest using the live chat option rather than email. If you don't see it, try this link:
https://help.ea.com/en/help-contact-us/?product=the-sims-3&topic=missing-game&category=manage-my-account&subcategory=find-missing-game
Make sure you're signed into an EA site (this one is fine) before clicking the link and that the location in the lower-right corner of the browser window is set to U.S. or U.K.
Alternately, try using the help site without being signed in. Some categories of issue allow you to proceed without an active login, and many of those offer the live chat option.
You can simply trash the installer that's not working.