(Make sure you turn your audio up, sorry it's quite low.)
You may be frustrated when you try to do push ups. I know especially for new boot campers it is quite frustrating. You always think like you should be able to do more, but the body doesn't quite seem to cooperate.
My suggestion as in this video is to use a simple stability ball.
You can begin at the very easy level by resting on the ball at about waist level. As you get stronger and your balance improves scoot the ball out towards your toes. Eventually you'll be able to do a push up with only the toes of one foot on the ball. (I'll do another video of that one after my triceps recover.)
Try it out and let me know how it goes