This topic drives me CRAZY. It comes up CONSTANTLY and is frequently confusing. There was a recent thread on one of the Amiga Facebook groups over 100 comments long. I gave up on it after a while, so many different people spouting off nonsense, lol.

If you right-click on CD0 from your Workbench you can edit a few of the properties. Device name, device number, and that's usually about all I ever see there. Sometimes it works, sometimes it doesn't but it almost always leaves people more confused because that's not giving them the full information.
Instead, drop down to a shell prompt and type:
Ed SYS: Devs/DOSDrivers/CD0
(without the space, amiga.org keeps trying to change what I'm typing into smilies)
This is where you can see the full properties of the file. You need to review parameters like FileSystem, Device, and Unit, and make sure they match your specific configuration. There's no "one size fits all" config, since everyone's setup is different. But once you match the config to your system, you should be good to go (and won't need to have anything specified in your tooltypes, unless they're parameters you want to access easily or change frequently).
See attached screenshot for an example of mine: