Here we have the chorus. In this part we'll basically just be strumming power chords using straight eighth notes.
In the video you'll see me down-strumming every chord, however if you'd prefer alternating between downward and upward strums that's totally fine. I prefer using all down-strums since to my ears it gives it a little more consistency in tone.
Lastly, make sure you're completely muting the 1st, 2nd, and 3rd strings. For example, when I play the first open chord you can see my index finger resting on the first strings so they don't sound. When you're playing non-open chords, still make sure to rest part of your index finger (or whatever finger is most comfortable for you) on those strings to mute them.