I too was in the central park and I also faced a situation which demanded knowledge of French like the user Aerovistae (Is the position of space and time precisions in this sentence correct?).
This time, however, I was approached by a non-French speaking beggar who wanted me to write something for his cardboard.
So here is what I wrote for him:
Je suis XXX. J'ai une famille avec cinq enfants mais je n'ai maison et nouritture. J'ai besoin de votre aide, s'il vous plait.
How could I have written a better paragraph (perhaps in terms of politeness) so that it could have given him the maximum benefit? Also, what do you think of what I wrote, is it correct?