Not sure of the laws now, but Its not legal to pedal on the street. Gotta be so many feet off the right of way.
Coconut's would be private property. You'd have to pay rent or get someone to allow you to do it.
A small cart with biscuits and coffee in the morning and hot dogs at night when bar was closing.
Hobie had 2 hot dog carts for awhile in the District, I only saw them after football games though and that was several years ago