Honestly I would say 5years and up.

Yes

You have to put it in water before it will work. My husband put his in the bathtub before putting in the lake.

Check whether the battery is properly connected or the battery charge level is too low

Make sure the remote has new/charged batteries.Make sure the controller is being aimed at IntelliPup's signal receiver.Bright sunlight will affect the remote's ablity to work

Make sure IntelliPup's battery is fully charged.Low charge levels will cause poor functionality.