Hi, I would probably recommend a couple of sheet sets in the cupboard. It is always handy to have spares, unless you intend on washing 24/7!

Our DD's only fitted in the bassinet for the first 3 months anyway, so we never worried about buying bassinet sized sheets, we just made sure we tucked the cot ones in tight.

Go for good quality mattress protectors, some of the thinner ones slide all over the cot underneath the sheet. Or make sure the have elastic to hold them in place.

As far as blankets go, I always used the woven cotton blankets. Depending on how you heat your house though, wraps may be enough.

Merry Christmas.