Hi gymbaby12,
Having gone through the troublesome and tiring process of learning a kip myself, I'd say there are a few reasons/tips on why you may not be making your kip:
~Unlike in level 4, you don't keep your legs in a stiff pike position. You need to 'extend' or arch at the very end of the first part of your kip, or when you are about to start moving back up onto the bar
~Do not bend your legs, trust me, it just makes it harder
~Throwing your head back is one of the hardest problems i faced learning a kip. Look over the bar to get a nice hollow shape.
~START WITH YOUR HANDS ON TOP OF THE BAR!!! Believe me, you cannot shift your hands and end in a nice position if your hands are barely hanging on. (this is a bit hard to explain)
Please tell me about your kip, I'd love to help you make it!
-GCG