Hey hun, here in Southampton they have a charity called Scratch that will donate basics for people in your situation. When I moved into my own flat 2 years ago after OH and I broke up last time, they gave me a bed, some tables, could have got sofas (but I had already ebayed a pair for £30!!), cutlery, plates, mugs etc. I think I just had to pay £10 for delivery.
https://www.frn.org.uk/need.asp
The website above should tell you if there's a similar scheme in your area, I hope there is! I was referred through the Domestic Violence team (wasn't on benefits) so I'm not sure what the requirements are, but hopefully someone there might be able to help x
Edit: I'm not sure exactly where in Northamptonshire you are but https://www.spencercontact.com/default.asp seems to be the best one, and if they don't cover your area they have numbers here: https://www.spencercontact.com/default.asp?id=13 that cover some other areas that might be helpful.