Quarantine Tank and what to do first?

I have a 10 gallon quarantine tank set up, I was wanting 2 cleaner shrimp, and some fish, I was originally thinking I did not have the quarantine inverts, but after further investigation some people say to quarantine them when I was reading on a different site. The reason I ask is because if I buy fish and use copper to treat them in the tank, I should not put any inverts in that tank ever again from my understanding correct? So if I do have to quarantine inverts I should get them first, and then fish?