This is a very cool tune by Big Mon. It is modal, meaning that it's key center shifts. It's a very common thing in Blues, Bluegrass, Mountain Music and other styles. Sometimes this song is in A major, sometimes it leans towards A minor, and some times it changes even more than that. It's very important to make listening part of your practice. Don't just try to understand where to play "the right notes" try to memorize what the right notes sound like. Use the Tunefox player and Spotify or Apple music links. Make regular listening a part of your practice.
The main arrangement here is a bit simplified for ease of access and playing. The licks have a bit more embellished and authentic sounds for you to explore.