Starting off with a bigger boat may doable, but I'm not so sure.
I caught the sailing bug in 1995. At the time, my wife wasn't so sure about buying a boat; and showed me a newspaper ad for a local sailing co-operative. Our first year was spent day sailing in O'Day 20's. Trust me, we made every mistake that was possible to make.
I quickly learned that it was easier to get out of those mistakes on a smaller boat. It was also easier to learn how to get underway and dock. By the time I was docking Catalina 27's, it wasn't so bad.
Last year, we finally took the plunge and bought our own boat (still social members, though!). I don't think the transition to 29' would have been so smooth if we had tried to start there.
At the end of the day, however, it is up to the OP. I think there is something to be said, tho, for starting small.