Pandas should already be installed, as it is installed with GeoPandas, but if it has not yet been installed, use pip to find it in the PyPI.org repository:
(mapboxenv) C:\Python3Geospatial>pip install geopandas
If you have any issues installing these modules on a Windows computer, explore the pre-built wheel binaries here (use pip to install them after download):
https://www.lfd.uci.edu/~gohlke/pythonlibs/.
