Watch the Freedom Rock online guitar lesson by Angus Clark from Essentials: Rock Rhythm Unplugged
Lessons in this example: chord muting, aggressive and consistent rhythm playing, playing fills.
Watch the left hand during this example for how to fully mute all six strings when you want to get a percussive sound from your strum.
Listen to the accenting on the right hand. This is meant to emulate the back beat you would get from having a drummer playing with you.
Playing fills between the chords is a great way to get around covering for a guitar solo section when you're the sole instrument on stage. It takes a bit of practice to find fills that fit and that will bring you back to the chords in the right way. Once you've got a few of these worked out, you'll find it's much easier to keep the rhythm together and do a bit of riffing in order to spice up the arrangement or cover for a solo. This is not the forum for all your scale work or tapping licks, just keep the energy going and don't lose the time and you'll be everyone's hero.