Yes! The bathrooms are located inside, and dances will be happening inside as well.
Yes, there is parking onsite. Once you've turned into Chateau Lill, keep right and there will be a large grassy area to park in. To get to the ceremony lawn, walk around the left side of the building to the back. (See image above)
Dressy casual - we want you to be comfortable! Also make sure to bring a coat for when it gets dark out! It's going to be in the 50s in the evening.