Welcome to the Zone
Regarding meals, if you have 4 blocks for breakfast, lunch and dinner you got 12 blocks right there, so you're missing 7. 2 blocks mid morning, 2-3 for tea, and 2 before bed. That makes 6-7. What time do you work out? You might want to have the 3 blocks right after the gym to replenish yourself. Juggle the blocks around but you will be looking to be having a bite to eat approximately every 3 hours. A recommendation I always make is to increase your block number 1 or 2 blocks, to account for building muscle and enough calories to cover your calorific requirements. The Zone is a muscle maintenance diet and therefore allows for little to no muscle increase. Keep calculating your block number every week or so to check your progress and see if you are still inside your same block number.
Regarding feeling hungry about an hour after eating, this could be because of excess protein. There are three ways of knowing if you are eating balance or not. If you are hungry shortly after eating you had too much protein, if you are sleepy too many carbs, and if neither of these two you were spot on. Give the Zone a week or two before making any tweaks, we are all different and the same amounts or times don't apply universally. Don't forget to increase your fat intake 2X or 3X for fast energy. Again, you won't see the benefits of this until you are well inside the zone, and the body takes between a week or two for this to happen.
As you might be aware the best CrossFitters tend to be Zoners or Paleo eaters, so you made the right decision.
Good luck and let us know how you get along!