The commissioners provided for in this section, along with the mayor, shall be known collectively as the commission and shall have the powers and duties hereinafter provided. The commissioners first elected shall qualify and take office in the manner hereinafter prescribed on the first Monday in October following the date of election, and thereupon such city shall at that time be organized under the mayor/commission/city manager form of government provided under this chapter and shall thereafter be governed by the provisions of this chapter.