Unlikely to be anything. If you're lucky you will have wallpaper on the walls. No carpets or curtains probably... Possibly not even curtain rails or poles.
My friend was given a bungalow 5 years ago, and she had to carpet it throughout, put wallpaper up (walls were painted but looked shit,) and she had to put up curtain poles, and curtains in the lounge, (and 2 bedrooms and hall,) and blinds in the kitchen and window.
She moved from a private let flat that was furnished and carpeted and had curtains and blinds, and when she moved; putting in the carpets, curtains, and blinds, and vinyl flooring, (and decorating and wallpapering the place etc,) cost her a fortune.
Around £5K in total for the removal costs and all the decoration and curtains and blinds and carpets. The council rent was cheaper, but it took her about 4 years to recuperate the money. Was a lifetime tenancy, so will pay off eventually, but she is only just seeing the financial benefits after having to fork out so much money. Got £100 decorating voucher! Just got a few cans of paint out of it! £100 goes nowhere!
It's great to get social housing, but it costs LOADS to furnish and carpet it and buy curtains and blinds and laminate flooring etc. The council provide fuck-all. Indeed, if the previous tenant leave stuff, they remove it, which is stupid! And annoying!
As for how long after the offer does someone move in? Depends on how much work they have to do. Could be 2 weeks to a month, could be 3-4 months.