I'm not sure what you are getting everytime you open Photoshop,but if you get the "license this product" popup, just sign in with your Adobe ID, and agree to the terms, or open the Creative Cloud App, and sign into your account there, and it should also activate your product.
A third way is to go to Photoshop's Help menu and look for your email address and click on it if (sign in) is next to it.
Worst comes to worst, call Customer Support and they will help you with the activation part.
The loging in on the App did it.
Thank you very nuch for tour help.