Hello Jemmie 29, welcome to Stamp Community!

I found it on
ebay Worldwide.
Your stamp is stained (looks like anyway) and thus devalued by that damage. Used is less than new (mint or neuf in French).
France 1959 catalogue Yvert et Tellier (French) #1231.
http://www.ebay.com/itm/FRANCE-MOIS...em27d494e855
Normal value is minimal, or 10c to 20c for a good copy.
The cancellation or cancel is from Pl.Grimaldi or Place Grimaldi in Nice, France. Not sure of the dating on it though. Neat!