Pack what you think you need, then get rid of a third of it. If you're like most you spend most of the day in swim suits. First trip I had two sets of swimming trunks and way more regular clothes then what I needed. My wife probably took 6 swim suits with her. I only take one pair of "dress" pants and can wear them twice if need be. I think I took 2 collared shirts for dinner. If I am not in my swimming trunk I will be wearing cargo shorts and a t-shirt of "basketball" style shorts when roaming round during the day. One pair of sneakers, a pair of sandals/flip flops and a pair of dress shoes.
There is a thread on "must have" or "must take" items. Do a search and you'll have a ton of replies to look at.
We/I never left the resort. My wife did the Margarittaville trip with friends and had an OK time. They actually got a cab and left early, saying it was more of a tourist play and the drinks and food were expensive. Other friends went to Ricks Cafe and stated that it was better and more fun than Margaritaville. Everyone loves the Catamaran Cruise. We did snorkelling, diving and the glass bottom boat. We did a good bit of the activities at the resort.