How to buy a sims 3 world from the store?

Johnnydeppgirl  The best route is to buy the world through the website, for example:

https://www.ea.com/games/the-sims/the-sims-3/the-sims-3-roaring-heights/buy-microcontent
https://www.ea.com/games/the-sims/the-sims-3-worlds-bundle

You should receive an email confirmation that includes one code per item.  (Make sure your address is receiving emails from EA in general, or that you can dig them out of the spam filter.)  Register these on the Sims 3 Store site, not in the EA App, for best results.  Sign into the site with the same credentials you use in the EA App, scroll to the bottom of the page, and click Redeem a Code.

For more information on registering or installing Store worlds, please see the first post of this thread:

https://answers.ea.com/t5/Store-Issues/Sims-3-Store-world-can-t-register-install/td-p/12619800