when i download cc it says there is no application to open it

@micalleffamilyThat's because you're not supposed to open them. The files can only be read by the game when it's starting up and only if they're place in the correct location and in the correct folder.
Read this pinned thread on how to properly install your CC.. https://answers.ea.com/t5/Game-and-Mod-CC-Issues/FAQ-How-to-use-Mods-CC/td-p/8781409

Edit: I notice now that you're using Mac. There's a thread for that as well.. https://answers.ea.com/t5/Technical-Issues-Mac/READ-FIRST-Sims-4-Mac-Help-Guides-and-Troubleshooting/m-p/4612394#M166