The members of the charter commission shall file their oath of office with the county clerk prior to the first meeting of the charter commission. The clerk shall give notice, by certified mail, to each member of the commission as to the time and place of the first meeting of the commission, which time shall be not less than 10 days nor more than 20 days after certification of election. The county clerk shall be the acting presiding officer for the commission and shall serve until a permanent presiding officer shall have been chosen from among the members of the commission.