Searching for accommodation for a six-month stay

I am a student looking for accommodation for my six-month internship in London, starting on February 23, 2026. I might come a few days earlier, but not before the 16th.
I’m looking for either a shared flat or a place on my own. The closer to the city center and the more affordable, the better.
The essential features I need are broadband internet, a kitchen, and a fully furnished apartment.