I installed the Creative Cloud correctly. Ok
Right next to Premiere there was a link called "Evaluate". According to Adobe's website, it should be written "Install". But ok.
I clicked it and it started downloading the app.
But now, I click on top of the app and nothing happens.
According to Adobe's website, there should be a button called "Evaluate", but instead it's written "Installed" and it's not a button.
So I just can't open the app.
What CC subscription does your AdobeID currently have associated with it? Installing CC doesn't mean anything. Go to www.adobe.com, sign in with your AdobeID, click Manage Account what plans and services are currently associated with that AdobeID?
The button will say Evaluate before the product is installed and when the CC app doesn't have licensing information for the app you are wanting to install.
Either you don't have a license to use Premier or the CC App doesn't know you do because you just signed up for one and the CC App hasn't checked the licensing info since.
To get the CC App to re-check what licenses you have, click on the gear at the top right of the CC Desktop app, click Preferences, then Sign Out. Reboot. Sign back into the CC App and then see what it thinks about Premier.
None of these instructions has to do with the app not doing anything when you click on it, but you didn't say whether it is the CC App that's not doing something or the Premier app that you've either downloaded or maybe installed, and to properly guess what might be wrong, it's necessary to know what your account has for authorized subscriptions.