Just bought a new unit. Connecting via Winbox, I should say attempting to connect, results in "wrong username or password". I'm using the typical default, "admin", and blank password. I'm trying both MAC and IP connect. I've (I think) reset the router several times (unplugged power, held in reset, plugged in, waited for flashing green light - the big one on front, release reset).

Am I doing something wrong?

Read the sticker on the little hidden tab on the back.

It contains something called... password.

Thank you. The combination of "hidden" and previous experience with Mikrotik devices made it so I was not expecting such.

Read user manual.
It's in there.