how many 24x24 pieces you get

You get eight (8) 24x24 pieces.

The Gold Zinc color is sold with a door. The black - you can purchase it with or without a door. We bought 2 24"x30" without doors and one with. We take them with us camping. Works great for our 2 Bostons-1 is 40lbs the other one is 28lbs.

can 2 of these be put together

I'm not positive, but I would think so, since the panels all come in one string and the ends can be put together to make a pen. You would just attach the end of panel set 1 to the beginning of panel set 2, and then close it off by attaching the end of panel set 2 to the beginning of panel set 1 to make a pen. Or just leave one long straight set of panels by just attaching the two panel sets in the first spot.Hope this helps!

Would kittens, less than 8 weeks, be able to climb out of this?

Ha! I had the same idea, but quickly learned that kittens develop climbing capabilities very young. I had better luck containing them in a large crate. Actually, I had two and they took over the entire room within a week. Such fun but definitely a handful. Enjoy!