1. Transport. It’s worth knowing your way around it. Even though you are busy and only here for a short time. I suggest you do some calculations: work out how much you spend and what it is worth buying in terms of travel cards. Buses can be a cheaper way to travel around London than the tube although getting used to the different routes/ times can be tricky also certain times of the day i.e. with more traffic but it’s definitely an alternative worth thinking about and not dismissing.
3. Sport is also a good way to meet others. Gyms can be expensive but signing up for a cheap trial period is a good way to keep costs down. Gyms usually do introductory offers, and if you can work out something clever out you could just rotate numerous offers so you never have to pay full price membership! Groupon also do gym deals. Look out for cheap yoga listings on the Broke in London website too.
ParkRun is an event held every Saturday at 9am in various different locations. It is totally free: just sign up, print your barcode and go along to join a 5km run round your local park (check on their website to see where the nearest one is to you). It’s very friendly and community-minded, and there is coffee afterwards so you can meet fellow runners (and you’ll see Hannah if you go to the one in Finsbury Park).