No animal sales on fb. However, there are farm groups, homesteader groups, etc where one can make connections to get animals.
CL does have a section to sell animals.
Currently many farm stores in my area (Ohio) are selling fall chicks. Fewer breeds than in the spring, but still several breeds. Yesterday I was at one farm store and they had 3 choices of egglaying breeds, and an additional 2 breeds sold out, and also meat chicks. So, call some farm stores...