Can I see my own password while already logged in to my user account?

Then what would you suggest I do? Previously the iMac was always safe in a room only I have access to, so there was no risk of anyone ever turning it on and gaining access to the content. So I had it set to "log in automatically." But now I might move the computer to a place slightly less secure, where I can't guarantee that I am the only person who would ever be in the same room as the computer. But if I don't know the password, and I have no way of finding out what the password is, then I can never change the setting for the OS to require a password to log in on startup, because then I'd lock myself out too! It seems my only option would be to save all the data to an external drive, physically destroy the computer, and then migrate to a new computer that I'd have to buy. Seems extreme.

Do I need to know the old password to reset the password using the Terminal technique you describe? I want to be very careful not to accidentally lock myself out, and I don't want to start the Terminal process and end up making a big blunder.

Hmmmmm...but this Apple support page seems to say the opposite:

"Start up from macOS Recovery,

...turn on your Mac and immediately press and hold Command (⌘)-R until you see an Apple logo or other image.

If you're asked to select a user you know the password for, select the user, click Next, then enter their administrator password. "

That seems to state pretty clearly that I would need to know the password to restart in Recovery Mode (Command-R). Should I be nervous?

Just so I'm completely clear on this:

-- If a person has previously set the settings so that an admin user is logged in automatically at startup, and then he restarts in Recovery Mode, he will then be able to get to the "Utilities" option and choose Terminal, because he will have already been automatically logged in at startup even in Recovery Mode.

-- But if a person has previously set the settings so that an admin user is NOT logged in automatically at startup, and then he restarts in Recovery Mode, he MUST then know an admin's user password simply to get past the start screen.

Correct?

Otherwise, if this wasn't true, then any random person could then take any Mac (for which they did not know the password), and then startup in Recovery Mode, go straight to Utilities>Terminal>Reset Password, without ever needing to know a password to begin with, and thereby gain access to the computer -- which would completely defeat all the security measures and the reason for even having login passwords in the first place.

So you seem to be saying that I will be able to get to Utilities>Terminal because I will already be logged into my account while in Recovery Mode. Right?

On a related note:

If I can use Terminal to "Reset Password" while in Recovery Mode, then can I also use Terminal to "Reset Password" while just in normal mode -- i.e. having started up normally and not in Recovery Mode? Or does Terminal's "Reset Password" command only work when in Recovery Mode?