Here "kingdom" refers to God's rule as king. Alternate translation: "concern yourselves with serving God, who is your king, and doing what is right" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This can be stated in active form. Alternate translation: "God will provide all these things for you" (See: [[rc://en/ta/man/translate/figs-activepassive]])