This is definitely something to put at the top of your to-do list. Make sure you're covered for the adventure and it's a level of cover that you are satisfied with. Some insurance policies will have a clause against this kind of event- so check this. Similarly if you are seeking insurance, you might find it helpful to clarify that this a amateur, non-professional Adventure, with no prize money.
Make sure you don't invalidate your insurance by driving without the correct licensing.