QHDragon, best of luck at the show and have fun!!
Just be VERY careful, as some of the others have said...has your horse ever been on a x-c course before? The reason I ask is because my mare Sandie is VERY honest and will also jump most anything I point her at (as far as show jumping goes). But that ALL changes on the x-c course! I just got into Eventing this summer so this was our first year on x-c (for both of us) and I ended up falling off twice when I wasn't supporting her enough and we refused the jumps (INTRO jumps I might add...they were only 1" at the highest, and we can jump 2'6" in the arena at home).
Turns out she was nervous because she'd never been exposed to things such as logs, black tires, piles of rocks, piles of hay, and brush boxes, so she was afraid of them and so was I...a bad combination indeed!
And because I was so used to her just going over everything, I wasn't supporting her enough and didn't even realize it, so that caused the refusals.
I'm not saying this to scare you, because I'm sure you'll do fine!! But just remember to STAY BACK and support your horse all the way to the base of the jump and DON'T LOOK AT IT lol...I kept doing that and ended up on the ground both times haha!
Look ahead, support your horse so he feels confident, and sit back, shoulders back and you'll do fine!
Let us know how it goes!!