What laws, codes or regulations that prohibit me from displaying information to help homeless and low income families on city grounds.

I have been told it is against the law and if so wish to work to change the law but city hall will not inform me of what laws I am breaking, it is like pulling teeth. I am currently having to pass out the information and it appears that there are many who are not aware of the resources. I will distribute the information to public place (such as the library, court house, Katz terminal, city hall, etc...) and work on finding funding to produce the information. I was informed that I will only get 5 minutes to bring up the issue at a city board meeting but I need to know what I am up against, what laws. I am not good with speaking to people. Is there a pro bono lawyer that can help, as I cannot afford one?