It's worth splashing out on a decent duvet and pillows if you can afford to (you're going to spend a lot of time in bed!), but if you're on a budget, you can't go far wrong with Wilko's Double Quilt and Pillows Essential Kit (£20). The quilt is 13.5 tog which is perfect for the colder months, and the pillows are washable, so they should last more than your first year, even if you're a serial drooler (no judgement).