The best way to learn routes through London is trial and error. Pick a land mark a good distance away, for example Selfridges on Oxford Street, then just try and get there. You'll have to stop and check the map loads of times. There's a handful of main routes through London, e.g. the Hipster Spice Route ™ East to West through Old Street and Oxford Street. Learning those will help.
The best way to learn routes through London is trial and error. Pick a land mark a good distance away, for example Selfridges on Oxford Street, then just try and get there. You'll have to stop and check the map loads of times. There's a handful of main routes through London, e.g. the Hipster Spice Route ™ East to West through Old Street and Oxford Street. Learning those will help.