It looks like it starts at a low enough level that you should be fine without a programming background.

Though they suggest Garrett's book [1] as a companion to R for Data Science in the Prerequisites section [2].

> And is R the appropriate language to learn?

I'd think so. Possibly either R or Python, or both (if you want to get beyond Excel).

[1] https://www.amazon.com/dp/1449359019 [2] http://r4ds.had.co.nz/intro.html