Decide Where You Are Installing
Before you can install the macOS 10.15 beta, you need to know where you will install it. There are a few options, and we will share the best path to take if you can.
The best place to install the macOS Catalina beta is on a spare Mac. This will let you test the new features and experience the update without worrying about losing any files or interrupting your workflow.
The next best solution is to create a partition on your primary Mac and then install the macOS Catalina beta there. This will be a clean install and it will keep it separate from the files and apps you use all the time. This is a handy way to keep the beta with you without carrying a second machine.
The third option is to install the macOS 10.15 beta on your only Mac as the primary operating system, similar to how you would upgrade this fall. This is risky, and we don't recommend that most users go this route. If you do, the next step is even more important.