FT, I used to cycle from Surbiton to Covent Garden, its one of the things I truly miss. Start by doing twice a week if you can and just work up to three or four. Make sure you include Richmond park, early mornings plus no traffic and the occasional Stag showing off are sublime experience that sets you up for anything. My route was Surbiton, Kingston, Richmond Park, Roehampton, Lower Richmond road, Putney Bridge, New Kings Road, Lots road, Embankment, Parliament square up to CG, if that helps.