Here "wars" probably refers to fighting between countries, and "riots" probably refers to people fighting against their own leaders or against others in their country. Alternate translation: "wars and rebellions" or "wars and revolutions"
Possible meanings are: (1) The end of the era in which the disciples to whom Jesus spoke were in at the time. Alternate translation: "the end of the age" or (2) The end of the heavens and earth as we know them. Alternate translation: "the end of the world"
Implied word can be supplied here. Alternate translation: "will not happen immediately after the wars and riots" or "will not happen immediately after those things happen" (See: [[rc://en/ta/man/translate/figs-explicit]])