There will be linens (bedding covers) for 5 persons. You have to put them on yourself. There will also be towels for you, so you do not have to bring any of that.
If you rent a boat, the key to start the boat will be in the boat.
In the basement you will find garbage bags that you take to the next village and drop it in the container in the neighboring village that says "FOR HYTTER" (For cottages).
Note that the light to the basement is next to the fuse box in the entrance hall.