What do I do to unlock my account?

When you initially set up your Mac you were asked to create two passwords - an Apple password and a computer access password. The second one will unlock your Mac. If you do not remember it you will need to click on the link below to create a new, different Apple password and your Mac access password. Then, write them down and save for the next time you need them.

Change or reset the password of a macOS user account - Apple Support

Rscott55 wrote:

I can’t open my Mac Pro because it says the account is locked

"says" locked....(?)

If your Apple ID is locked or disabled

Lock icon

If your Mac is using a firmware password, the lock icon appears when you try to start up from another disk or volume, such as an external drive or macOS Recovery. Enter the firmware password to continue.