I'm sorry if I posted this in the wrong place, couldn't find a more appropriate section for my questions.

I'd like to build up 4 concrete walls to enclose a rectangular area, sitting over an existing concrete slab on the side of my house. The rectangular area is 12' long by 10' wide. The 4 walls are to be 9" tall and 9" wide.

[1] What can I use to make the concrete former? Is timber the only solution? How do I secure the concrete former to the existing concrete slab?

[2] Do I need any reinforcement within the wall, like wire mesh or some type of rebar?

[3] Is "Quickcrete" from Home Depot suitable for this project?

Any other advice would be greatly appreciated.
Thank you!!