This is a fantastic traditional tune popularized by the Carter Family. Most guitar players play this song in C, so this version of Wildwood Flower is catered for beginners learning about C position.
This melodic version of Wildwood Flower is a higher register break played mostly out of the root-position C chord on the 10th fret.
Wildwood Flower uses a lot of 2/4 measures, so make sure you have the melody clearly in your head while playing the backup part. It's helpful to sing the lyrics out loud to ensure you're in the right spot.