Luggage and bags:
Always travel easy -
Clothing/Shoes/Weather Gear: Be prepared for cold - hot - rainy days.
Toiletries and Medical Supplies: No need to bring anything as all is locally available,. unless you need your special kind of toiletries and medical supplies
Photo Equipment: All films available
Camping/Beach/Outdoor Gear: In case you like to do some camping it is allowed along the shores of the Rhine in particular places.
Miscellaneous: During early spring and fall foggy weather may suddenly prevail
A tripod and a camera that can take better night pictures than mine ;-) I had a tripod but it wasn't much use as my camera couldn't do what I wanted it to do... maybe I should re-read the manual ;-)
Camping/Beach/Outdoor Gear: A flash light! Some bits of the park are really dark at night so it's easier to walk and to find your way if you have one. We didn't have one, it would have been too scary if I had been on my own!!!!!!!!!!!