New to day sailor

I have two holes that run from the cuddy to the cockpit, what should I use to plug them or use nothing at all? I have the Starboard side cuddy door, the port side is missing, were can I get a drawing of how the old door looked, so that I could make my own, or can I just flip the other door over and trace it and cut it out? Were can I find my hull number, I would like to add the numbers to my sail.
Thanks, Eric
Thanks, Eric