Under the video there is clickable tabs, look for notation tab.

In the song she plays 2 bars of C, then 2 bars of G and it repeats like that.

Try and play along with the beat of the drum. (shes strumming in 1/4 notes, 4 beats to a bar).

So start with C and count 1.2.3.4/1.2.3.4/(G)1.2.3.4/1.2.3.4/(C)1.2.3.4/1.2.3.4/(G)1.2.3.4/1.2.3.4......... and so on.

I hope this is helpful in some way.