Making a list of necessity items is a good way to begin any camping trip. Then make another list for "just in case" items, such as being weather prepared.
Make sure you have enough water. You may also need water to brush your teeth with or sponge bathe. Bring clothes that can get dirty. Most importantly be open.
If they allow it, bring lots of water and non-perishable food. Take as little gear and valuables as you can. Pack sanitary wipes and prepare to get dirty.