Undies??? Jammies? Socks, shoes? Beyond that I think you have it covered.
That is where I need it too, the PJ's I like a fresh one each night w/o doing wash. I take loungers to do double duty. They are the Fruit off the loom shorts and SPRIT bottoms and tops from
SAMs Club. I can war to the pool, after shower to sit outside with the kids. Early AM trip to the Value cafateria to toast Bagels toast (If I didn;t pack a toaster

)
That too, water hot pot, toaster, carry lunch tote with water and kids sips to park. I also took a Coffee pot and left in the fridge swap I was part of.
So that ment paper plates, cups, bowls for cereal, We had a car so did a run for food.
I needed an extra pair of shoes, to go with the sandles, plus my sneakers.
A jacket, THe one thing I found is you can never predict the weather. Two years ago in Oct 06 we had 99* for several days, the day before we left it was 48* and I froze without a Jacket or long pants.
Another trip about Jan 99 it was sleet storm when we left PA and got there and record 88* heat down there, I planned on cooler days there and used up all the shorts.
At the park there are water areas of play for the kids, means a back pack and plastic bags for wet things. Oh and wet play shoes to get wet,
I decorate my window, lime green
Dis lights, potatoe heads, mini characters, which meant an extention cord and suction cups to hang lights.
Have a grand trip,
di