Wear whatever is comfortable. It is recommended to have a sturdy pair of broken-in trail shoes, boots, or sneakers. It is preferable to dress in layers and wear clothing that will wick away perspiration and keep you dry and comfortable
Not much. But you can bring your own drinks and food and store them in a fridge on a yacht. We do suggest you bring appropriate clothing to fit the season and a day pack to carry extra snacks and water.