I have only 3 sheets for DD's Cot, had them since the boys and two mattress protectors. I definitely don't change them every day or multiple times over the day. If you have a chucky baby you can put cloth napply unfolded as a 'protector' under their head while they are not moving much.
As a NB you may 'swaddle' and then put perhaps one blanket over them if it's cold.
We also don't have any blankets as once they start to move a bit they risk getting tangled up or under them.
IMO one of the best things we have is the gro bag or snugtime sleeping bags/suits.
The bassinette I also only had 3 sheets and that was plenty.
The other thing to keep in mind is the size of your baby. Not all babies fit in the bassinette for long (DS2 only lasted 1mth). I used the Cot during the day so as to get them used to sleeping in it, some babies don't transfer well from Bassinette to Cot if they have never slept in a Cot before. Cots can also take up to 6wks to order if they don't have floor stock of them.
I have yet to use any of the top sheets yet as DD is in a gro bag at night and will be for quite some time most likely until she goes into a bed, that's how it was with both the boys.
The cot I have converts into a junior bed and that's when I started using the top sheet and blakets.
Good luck with it all. Try not to get caught up in the 'wants/must haves' too much, easier said than done I know , you may end up with a whole heap of stuff brand new with tags to sell on Ebay.