I just installed RetroPie on a new Raspberry Pi 3, I'm currently connecting via SSH to configure it, with the default Username (pi) and password (raspberry). I wanted to know how to change this password (and if possible the username).
I've been reading other questions about similar things, but they're all on Raspbian or different distributions and the log in password is always involved, and since RetroPie doesn't have that I'm not sure if the answers to those apply to RetroPie.
As RetroPie is built upon Raspbian most commands that work on Raspbian will work on RetroPie. So to change the password for the logged in user use the passwd command and follow the prompts. You mention wanting to change the username, but don't explain why. Without a good reason I would not suggest this. A better alternative may be to create a new user using the adduser command. You can read more about these commands by referencing the man (manual) page (i.e. man passwd or man adduser).
