This arrangement is in G minor tuning. If you are in standard banjo tuning(G Major) you'll need to drop your B string down a half step to B flat. Make sure you are familiar and comfortable with some of the common rolls before tackling this arrangement. Alternating thumb, forward backward, foggy mountain, forward, and backward rolls are all used to keep this melody moving like a band of wild horses. It would also benefit you to be familiar with the melody of this tune. If you don't know the song and can't hum or sing through the tune, check out the melody tab before diving into this one.
Be sure to check out some of the great licks here. The licks will show you ways to incorporate different rolls and typical Scruggs style embellishments to get different sounds from the same melody. Saddle up and enjoy the ride folks!