144" is the diameter, 33" is the depth. The pool is 12 feet wide and 2.75 feet (2 feet 9 inches) deep.
No. it's 33" deep, AKA 2 feet 9 inches. As a male of average height (5'9") it doesn't even reach my hips, and just barely reaches the top of my inner thighs.
Filters only remove particulates in the water, they do nothing to remove bacteria, viruses, algae, parasites, etc. You will still need chlorine to kill any harmful organic material. Ideally, you also need an alkalinity buffer like sodium bicarbonate, and a chlorine stabilizer like cyanuric acid, but sometimes you can get "total solution" chlorine tablets that have pH/alkalinity buffers and chlorine stabilizers built right into them; nothing beats using a Taylor test kit and doing proper chemical adjustments, but the "all in one" solutions are usually "good enough" for a small backyard pool such as this. Something you might want to consider adding is boric acid, or its more commonly available counterpart, Borax laundry powder: Borax will keep the water clear, make it silky smooth, work alongside your chlorine to kill harmful substances, stabilize your pH, inhibit algae growth, AND it will kill off any wasps, hornets, and yellow jackets that decide to use your pool as their watering hole. There are plenty of videos on YouTube that show you the best way to use chemicals in your pool and cut through all the mystery and make all the chemicals and terms easier to understand; one such YouTube channel is Swimming Pool Science - watch a few of their videos and they'll tell you how to take care of your little pool.
33 inches = 2 feet and 9 inches from the bottom of the pool to the top of the lip.
It says 33” tall... that’s also the depth.
The pool is 33" tall and 12' across
Any fencing would have to be installed on the outside perimeter of this pool on the ground or a purpose-built surrounding deck structure. You cannot install fencing on the pool itself.