I am not a Pyxis user. There is a Quick Start tutorial for Pyxis if you haven't looked at that. https://supportnet.mentor.com/docs/201603070/docs/pdfdocs/pyxis_quickstart.pdf . I think it includes some examples for adding pins and power routing a cell. It might be helpful.
I think you can get the area of a cell/context or selection using the Report menu. If you don't see the area, you might see the coordinates of the extent of the cell. I am not sure how to get the wire length in Pyxis.