One of the all-time great folk songs and also very easy to play. In order to do the alternating bass on the C chord you can either hold the
chord as shown in the diagram below (with your ring finger on the 6th string 3rd fret and little finger on the 5th string 3rd fret) or you can just hold the standard C chord and alternate
your ring finger between the 3rd fret of the 5th and 6th strings. That takes quite a bit of practice but is easy once you get the hang of it. If you are a beginner and both of those
options are too difficult, just hold a standard C chord and alternate between the 5th string and 4th string, which also sounds pretty good.