Ron has a new iMac which he updated to macOS Catalina. But now he can't get it to print to his HP OfficeJet. He downloaded the latest drivers, but that hasn't helped. Leo says that those drivers may not be for macOS Catalina. Go into the System Preference page and see if it sees the printer. If it does, then select add and let macOS download the drivers itself. You may also need to remove the printer and then add it again.
Another issue could be that the drivers work with 32-bit libraries, and Catalina doesn't support that. So your printer may now be incompatible unless HP updates the drivers with 64-bit libraries. ScooterX in the chatroom says that if Ron goes to the HP site, it will detect the OS and suggests for Catalina is HP Easy Start version 2.9.1.002
Here are a few technotes to help -