Can you get beach chairs and umbrella at extra cost or does it come with lunch

The chairs and umbrella rentals do not include food. However, you can order food off the regular menu to-go from the restaurant. OR The Palm Shoppe in the same building does have select menus items that you can grab and go. They do have beverages and snacks too.

Not available, but you can sit outside on the deck listen to the waves and eat lunch

Not available there

Not sure, however There is many shops around you can buy some