You won't have any trouble finding a place to eat in Myrtle Beach. We love's Joe's Crab Shack at Barefoot Landing but there are your usual chain restaurants too. There is outlet shopping also. Just ask the concierge at the hotel because there are numerous places to go but some can be pricey. The beach right by the hotel should be very nice. Shouldn't be any need to go elsewhere. I have been there several times - but haven't stayed at the Dunes.
We just finished a week at the Dunes resort, and had a great time. The staff was great and very attentive. All the food, mainly lunch by the pool, we had was good as well. Depending on how crowded the hotel is, you may have to get up and reserve some pool chairs if you want an umbrella. There is not a lot of shade by the pool, and there is a silly routine where people go down at 7, reserve a bunch of chairs with towels, and go back to bed, or off to the beach. The hotel needs to do a better job on enforcing their no reserve policy. You are located only minutes from scores of eating choices. One of the best we found was the Chesapeake House, great seafood, great value. I would skip Greg Norman's place, overpriced and not all that good. Have a great time. Ask for Erin in the hotel restauraunt for breakfast. She was great.