I don't recommend North Myrtle Beach to be honest. I lived in Myrtle Beach about a year and half ago and now live in Pawleys Island, which is only an hour away.
A lot of the hotels in NMB are dated and the main stuff is on the strip. During summer, traffic to get to MB from NMB is horrible, especially if you don't know the back roads all too well like someone who has lived here for a bit.
When we would vacation here, my family loved staying at Compass Cove. It has changed since then, however we still hear good reviews about it.
I hope you all have fun while you stay here. Make sure to play some putt-putt, eat ice cream, enjoy the beach, shop, hit up the aquarium, etc. But PLEASE, and I beg of you PLEASE don't be one of those pushy "tourists" that treat the people that work at a restaurant/store/etc. like poop all because you're on vacation. (I worked in retail at the outlet mall during the summer and it was really bad). Deontology, treat someone how you would want to be treated.