thank you in advance for your answers!
Most of my international student friends will go home for the long holidays, especially in the summer, but you might be able to find a contract that allows you to stay all year around! Some university halls also offer this.
Many people in my uni (not a London one) will rent a house with their friends in first year, that you sign the contract for between November and March (give or take).
As I'm a home student, I often bring quite a lot of stuff back with me during the holidays, but after I moved out of halls during first year I was able to move all of my stuff into my rented house for second year, as the housing contracts usually start in July where I am.
I hope this helps a little