What we do....
Only ever take a back pack with the bare minimum inside - no hardsided rolling carry-ons which might be gate checked. When we get to where we are going we buy whatever didn't fit in the backpack and another bag to put it in that can be checked for the flight home. Extra bag will also hold souevenirs .
When we get to Orlando, we take a cab or rideshare to
walmart to buy whatever we need (including bottled water and snacks) and then another cab/rideshare to the hotel. Yes, we spend a bit more on the transport and extra bag and it takes a couple of hours out of our vacation but we never have to wait for our luggage or risk not having it arrive. Items purchased...enough socks and underwear to last the week, toiletries, sunscreen, razors, moleskins, bandaids, medications like antihistamines, tylenol, decongestant. Personally, i only ever pack a couple of sundresses, 1 swimsuit, 1 pair of shorts, 3 tshirts, something to sleep in, 1 pair sandals, wallet, phone (with charging equip), deodorant, lip balm, sunglasses and a poncho. I wear a shirt, a hoodie and a pair of sweat pants or leggings and runners/sneakers on the plane.
Gather the items you think you absolutely need and try fitting it all into a backpack. If it doesn't fit, be ruthless and start eliminating. I promise you don't need half the clothes you think you do. No one there knows you or cares what you look like.