Do you have any advice on what to do, how to prepare, etc., for a upcoming spur ride?

Whatever happens -- don't quit. Hydrate yourself and enjoy the ride

If you're not a Scout, get with them and brush up on those skills (I'm assuming you're in a unit with them if you're doing this). As I recall there was a lot of road marching involved and there were things like land nav, call for fire, and weapons stuff.