This is an EMOM (Every Minute On the Minute) workout. You set a timer for 5 minutes total, as the workout states. You complete 5 sets of push-ups, beginning one set at the start of each minute. i.e.:

Set #1 @ 0:00
Set #2 @ 1:00
Set #3 @ 2:00
Set #4 @ 3:00
Set #5 @ 4:00

That's it.

Hi, for this workout, am I done when I complete the set that starts at 4:00

Yes.