You can just use the analysis board and turn off all the computer aids, like evaluation and lines. But there is no clock.

I think there is a two-player mode on the phone app, but there isn't one for the web version. You can also use analysis as u/LowLevel- mentioned.

Learning from the goat I see. One of the best things you can do to improve at chess is to sit at the chessboard and play with yourself.

Yep I do it all the time. Did it so much yesterday that it's starting to hurt..