Could you please tell me how the...

Could you please tell me how the rooms are laid out or do you have a layout?

If you go to the resort website and click on the room photos, as you scroll through the photos the room layout will come up: https://www.marriott.com/hotels/hotel-rooms/myrow-marriotts-oceanwatch-villas-at-grande-dunes/

Is there a walk in shower available?

The master bedroom has a walk in shower. The second bedroom with 2 queen size beds has a tub/shower combo. If you are referring to a walk in shower for anyone with handicapped needs, there are rooms equipped with that but you should call the resort directly and request that type of shower. They will most certainly try to accommodate you.