I understand why you are changing arm slots, but you are going to have to earn the right to do this on your highschool team. Many highschool coaches would rather the ball come in with an arch on it for strikes, rather than give up a few bases on balls.
Changing arm slots, while very effective, can have an adverse effect on throwing the ball for strikes. For your first time out, maybe not a good idea.
I watched a guy yesterday in a JV game with very average velocity collect ten strike outs. All he did was change seams on his fastball, and probably threw less than ten curveballs. When I talked to him, he said he alternated between 4 seam, 2 seam, and no seam fastballs, and a big drop curve. What he had was command of everything that he sent up to the plate.
For your first time out, go for command. After you establish yourself, then you can start to confuse 'em.
Best of Luck,