In this song, you can either use the traditional folk style C chord that you see me playing in the video or a more modern version of the C chord that I teach in the 3rd Adventure (also called a Cadd9 or a Cadd2).
At this point, it’s not worth worrying about. You will learn the folk style C chord in the 4th Adventure. Mostly it’s a matter of personal preference. I used the folk style in this song because it’s most common in this style of music.
Learn what they both sound like. You’ll find both invaluable.