rug embridery

I know a little bit about embroidery, not much, and I have done lots of cross stitch.

The rug that I need to make is 120 inches long and 30 inches wide, it is a wall rug.

I have no idea how much canvas to get, or what kind to get, or what size. Can you help me with this? I do not even know where to begin. I have a pattern picked out as well.