BPF of course has the luxury of operating in a cheaper environment...
I'd say go for small and quiet for the PPL, somewhere with small circuits to keep the cost down. And check if you're paying Hobbs time or takeoff to touchdown, too. The cumulative effect of 15-minute circuits and 10 minute wait at the holding point will get expensive.
Circuits at my home base are 4 minutes... Fun if busy. Somewhere in between would be good!
Then when you have the PPL and the spare mental capacity, go somewhere busier.
My own trajectory was Welshpool - Oxford - Benson which was quite a good incremental process!