Your mum is obviously awesome
And I am intrigued as to who your family friend is now, very likely I know them (Sidney's a small place, everyone knows everyone). Subject?
Don't worry, the interviewers will generally go with it and help you along - they'll tailor the interview to the way you approach the problem. There isn't a 'right' way of tackling it necessarily, it's all about seeing how you think and stuff.
There's several science sites all over the city... for chemistry and physics your lectures are both at the chemistry department on Lensfield Road, which is about 15-20 minute walk. Earth Sciences and some biological stuff is on Sedgwick Site (not to be confused with Sidgwick Site) which is on Downing Street about ten minutes away. New Museums is home to more biological stuff, perhaps your maths lectures (and Chem Eng
) and is about five minutes away. Finally, the Physics department is a good 15 minutes by bike. Stupid Cavendish laboratory. But you'll only need to go there once a fortnight in first year at least. Generally since Sidney's in the middle, you're never more than fifteen minutes' walk from the useful places.
And Sainsbury's is approximately 30 seconds away from your room.