In case you don't know: If you buy sterling silver jewelry, it does need to be polished to remove tarnish.
This brought to you by just seeing a YouTube short from someone saying her wedding earrings weren't worth the money because the sterling silver is tarnished, and she isn't sure how to clean it.
You can either buy silver jewelry polish and bust out a clean toothbrush, or you can take it to a jeweler or jewelry counter, and they'll likely clean it for free or a small fee.
Also, these were Tiffany earrings she was saying weren't worth it, and while I have a good laugh at how tacky Tiffany's truly is, their quality cannot be questioned.
Just, if you buy something fancy, make sure you know any care rules so that you don't think you got hosed when you didn't.