Using FileVault to encrypt a Mac's hard drive.
This is recommended for users with macOS. It provides full disk encryption and is built into the operating system.
You will be asked to choose and confirm a "recovery key" (password). You should keep this safely and securely (in your paper files somewhere) as a spare in case you find you need it.
The password you use to log in to your Mac becomes the decryption key you will use normally (daily). The recovery key is like a master password to use in special circumstances if you need an alternative for whatever reason.
Your computer officer will be able to help you if you have questions about establishing encryption on your Apple Mac.