Nirvana - Polly

I just finished watching the Polly song lesson and find myself a little confused on how to play the song. I am able to play all the chords and the transitions between the chords. The problem I'm having is with the rhythm. The instructor did a great job of playing the song, but didn't spend enough time on explaining how to play it. For instance, in the tabs it clearly shows some chords being muted, the the instructor never covered that in the lesson. Also, are there any up strokes? Is the whole song play with 1\8th notes? These seem like really basic things that should be covered when teaching a song.

Any advice would be greatly appreciated.

Thanks,

Joe