9 Things to Do Before Installing macOS Catalina 10.15.3

Make Sure You Know Your Passwords

Know your passwords before you install macOS Catalina. 

When you restart your computer after installing macOS Catalina, you will need to log in to your computer and you will likely need to log in to your Apple account and to other apps. 

Ideally you will have a password manager like LastPass, 1Password or Apple's built-in manager to store these for you, but if you don't make sure you test logging into at least Apple and your email account.