I have a lot to learn - the 2 plugs, boom & cover

I'm lucky to have my Dad's day sailor 2.
Last year I sailed with out the plug but made it back to shore. I don't quite understand both of the plugs. I just make sure I have them both in when I sail.
As a week end sailor I take the sail and boom off the boat. My Dad thought i could leave the boom on and slide the sail off? Any advise on that?
I need a sail boat cover and if I leave the boom on or off will determine what I get. I also was thinking of sewing one myself. I saw the recommendation for the sailors tailor - $400 is a bit much.
What is a boom crutch?
I'll have more q's later. Like I said, I have a lot to learn.
Last year I sailed with out the plug but made it back to shore. I don't quite understand both of the plugs. I just make sure I have them both in when I sail.
As a week end sailor I take the sail and boom off the boat. My Dad thought i could leave the boom on and slide the sail off? Any advise on that?
I need a sail boat cover and if I leave the boom on or off will determine what I get. I also was thinking of sewing one myself. I saw the recommendation for the sailors tailor - $400 is a bit much.
What is a boom crutch?
I'll have more q's later. Like I said, I have a lot to learn.