Very interesting!! Thanks for reaching out!! If Connect is what you're focused on, you don't need to worry about RStudio Server Pro or RStudio Package Manager. However, you may unfortunately need to go through the same activation process for each if you do want to take a look at those products.
Did you have to go through the offline activation process because you are on a corporate network? I'm surprised the licenses did not automatically activate for you!
In any case, try the following commands - it looks like Connect may just need to be started?
sudo systemctl status rstudio-connect
sudo systemctl restart rstudio-connect
sudo systemctl status rstudio-connect
Then have a look at the UI to see if it is working:
curl -i http://localhost:5000/rsconnect/