Hi FreddyL,
There is a much simpler way then what Neal posted. The average user isn't going to want to enter terminal commands, too much information.
There is no DMG file for Catalina. To get the installer file for Catalina follow the instructions below. You will need at least a 16GB USB flash drive.
- Go to the App Store, this can be found by going to the Apple Menu > App Store or click the App Store icon in your dock.
- Once the App Store loads, type "MacOS Catalina" into the search box in the top-left corner and press return and click the entry for Catalina to go to the download page.
- Click the "Get" button. This will open Software Update in System Preferences and begin the download of the MacOS Catalina installer. Depending on your internet connection, this may take a while.
- Once the download is finished, the installer will open. Click cancel or quit to close it.
- Visit the site for Disk Maker X, https://diskmakerx.com/
- Download the application Disk Maker X to make a bootable copy of MacOS Catalina for other machines.
I hope this helps. If you have additional questions, don't hesaitate to write back and i'll be happy to provide more assistance.
