Financial aid usually depends on the school, and state (for the state grant). For my school, all financial aid stuff needed to be done by april first, though the 'actual' deadline for the state grant is May 1st.
It would probably help to have riding experience, but it may not be an issue, depending on the focus of the program. Is it medical, or riding based? Or more about management?
Most community colleges have a rolling admission, meaning you can apply at any time and can register for classes at any time. register as early as can to ensure that you get the classes you want.