When the members of a county port authority or county development commission shall have been appointed and shall have qualified as set out herein, they shall meet at the regular meeting place of the board of supervisors of such county, after giving at least five days' notice of the time and place of such meeting by publication in any newspaper published in the county seat of such county. At such meetings they shall elect a president and a secretary, who shall be members of the county port authority or county development commission, and adopt such rules as may govern the time and place for holding subsequent meetings, regular and special, not inconsistent with the provisions of this chapter.