These are the things I did before my first cyclocross race ( and helped I think)
1) look up YouTube videos on how to dismount/mount and practice for an hour or so.
2) try lower air pressure in the tires, for better tranction
3) take off bottles, cages, and saddlebags, etc so that they don't get in your way during the race.
Cross check is an awesome bike as a starter.
CX is ridiculously fun (or painful, depending on the perspective), start as soon as you can.
Good luck!