Assuming you will be using a tent, try erecting it first while at home. Be sure your cooking set up works. Seems odd while we are hearing of record heat waves, but be sure your sleeping system is warm enough and comfortable.
Yellowstone will be quite crowded. With covid still lurking, avoid crowds. There is plenty to see and do in Yellowstone, or any other national park, while not following the herd.
one or more gifts or other benefits from the co-op.