Sand jogging is challenging and you have that to use at the beach!
I’m assuming you’ve followed all the necessary procedures in order to use that area for your boot camps.
Look around the beach and use what is available… are there stairs, benches, maybe a recreational area with monkey bars?
As far as equipment, bands and tubes are inexpensive and travel/pack well.
Why not bring beach balls to toss and catch while doing crunches?
How about pool noodles to use in place of a body bar for forward reaches when doing squats or overhead extensions and then side to side.
You could always do circuit stations if you don’t have enough equipment.
I use my TRX at the beach and you’ll definitely attract those onlookers while using it!