Make sure you're at home a lot when the puppy is very new, and expect a good number of nights with very broken sleep.
Buy lots of kitchen roll, poo bags, disinfectant and some biological washing powder for accidents. There will be many of them. Also, a very light collar and lead.
If you can manage to find 2 beds - a cardboard box with blankets/towels would do as a back up just in case there's a wee/poo/sick accident in the middle of the night - the spare might be very useful. A hot water bottle and a big soft cuddly toy will help settle her at night too - and a crate if you're crate training.
She'll also like a few little toys - soft ones mostly at this age to carry round and play with. Empty milk containers and bottles are a favorite thing, tennis balls too.
Puppy proof by crawling round and looking for enticing things to chew - cables are a good one to keep out of the way. Have a check of the garden too for things like slug pellets or ponds/pools and fence them off. Although puppies can swim, they can't get themselves out of water reliably. I have a friend who lost her flatcoat pup because he wriggled out of a teeny gap in a sliding door and somehow got trapped under a pool cover. I don't think she'll ever get over it, and certainly won't forgive herself.
I'm trying to say, make sure your house is puppy proof, because even if you are quite sure you know where your dog is every second of the day; you might not. They move very quickly, are massively inquisitive and very quiet sometimes. At least if you loose sight of her and you've puppy proofed, you'll know she can't come to any harm.
The book a perfect puppy by gwen bailey is a good read and can be very helpful.
Investigate pet insurance and assuming you get the 4 week free insurance from pet plan with your breeder, make a note to take out the policy 2 weeks after you get her so you're not exposed to the risk of a 2 week exclusion for claiming which happens at the start of every policy.
Then get excited about it!