Ubuntu password

I have an ‘emphermal’ instance of Ubuntu (latest) functioning with a terminal login prompt
I figured possibly my username/pwd for dreamcompute would get me in there, but no.
Is there some default ?

Default username for all instances is “dhc-user”; the SSH key you configured in the dashboard will get you in.

What Andrew said is correct if you are connecting via ssh. If you are using the console for an instance from https://dashboard.dreamcompute.com/ , there is no login available for that console at this time, but we are considering options for future accessibility there.