Can I come in? I have cake! 
I think I was on one of these threads years ago, but I must have lost track of it.
eliphant, fold up bikes are pretty hard to ride. And £75 is very expensive! I only charge £20 an hour, and I provide bike hire if needed. I'd have a look around and see if you can find someone else - there must be more people around somewhere. Since you can already ride a bike, you really want level 2 rather than beginner stuff too x
I did Ride London - it was ace when it was flowing, but so many crashes! And I got stuck on leith Hill for an hour and half in the gridlock. I said never again, but I do want another go for a better time. 
I work in cycling, and I mtb and road bike.
Good lukc with the tri PhoebeMcPeePee! I've done a few, they are absolutely awesome. Much friendlier crowd than running races, or sportives ime. I've only ever done pool based tris so far, but I went for my first open water swim at the weekend. It took a little while to pluck up the courage to strike out away from the shore, but once I was out there it was utterly awesome. Hoping to do an olympic distance tri next year.
I don't really get the sighting thing. I keep looking, and the buoy seems to be in front of me but I'm sure I am still zigzagging!