The Sorrento Hotel website is here:

http://www.sorrentohotel.co.uk/

You could get the number 3 bus from near there to the main entrance, I think. Alternatively I'm sure there are bed and breakfast places that are closer.

I have no idea whether the Robin Hood even has rooms, it's just the nearest place I can think of. You had better contact them directly if you are interested:

https://www.eating-inn.co.uk/house/robin-hood-cambridge?utm_source=g_places&utm_medium=locations&utm_campaign=robin-hood-cambridge