Looks like a fun racer
. The insignia on the sail will give you a clue as to what boat it might be. Also most boats have a manufacturers plate or ingraving somewhere on the inside of the cockpit
For plugs you can look in a West Marine www.westmarine.com
catalog for replacement plugs or you can check at www.APSLTD.com
Beckson makes the screw or twist in type plug.
Some dinghies have two plugs, one for the cockpit
and one for the inner hull
beneath the liner. Make certain they are both in when you launch.