You got some very good advise there. You are very keen which is good but please listen to your body. 20 miles in 8 weeks is a hugh ask for your body which will put you at risk for injury, let alone trying to do it at the pace you are aiming for. Your body needs time to adapt especially as you just started running.
Thinking back, my primary school (for 6-10 year olds) didn't have a fence. Once classes were over we would just make our own way home and the parents didn't have to pick us up. We would also make our own way to school and not getting dropped off by our parents. The other kids would take the piss if they saw you being dropped off by your parents. I normally cycled the 3k to school as there was no bus from our house to the school. Haven't been back for a closer look for years so can't confirm if they put a fence up in the meantime.
I'm still wondering how the company pays for the places and other costs if the free massages are not there to temp ppl in buying the product? I can imagine that the place in London is not cheap to run looking at the prices for real estate in London.