NEC in the US limits a combined lighting / receptacle circuit to a maximum of 12. 12 light fixtures and 0 receptacles, 6 light fixtures and 6 receptacles, 0 light fixtures and 12 receptacles as long as the combination is less than 12. The breaker can be 15A or 25A and that requires 14AWG for 14A and 12AWG for 25A.