Need Help with Seven Nations Army Please

ok i am just starting guitar and i got the first bit of seven nations army, but about 45 seconds into the song he strums a chord a few times and i was wondering if anyone knew what chord it is, thank you.

if you have only just started it is a good idea to learn as many chortds as you can and get a good idea of what they sound like, then you can figure out chords to any song you want