I don't know the answer, since I don't use the Creative Cloud version, but I do know that if you search this forum, you will find the correct answer in dozens of threads.
You downloaded the creative cloud update by mistake. It will be necessary for you to uninstall Lightroom and then install using a download from this website:
This will not do anything to your catalog for your images. So after you install the appropriate version you should be able to start right where you left off.
Did you buy the Photography Plan for $10/month that includes LR+PS-CC? Or did you buy LR with a serial number?
The two LR’s are licensed differently.