Hi Beverly, I walk every day but don't do as much as the 6-7 mile walks on this trip very often. I'm planning to do a few longer walks in the coming weeks to get in practice.
I am planning to take strong walking shoes (not boots) and also my walking sandals. I much prefer walking in sandals but will take advice about when we get there, as they're not so good if the ground has sharp stones. I think it should still be pretty hot there in October, I'm expecting to wear summer tops/shirts and cropped trousers unless we need to cover up because of insects etc. (Not shorts. You really wouldn't want to see my legs in shorts!)
I also really love to swim and will be packing my snorkel and mask.