Side scrooling game

I have a good idea for a side scrolling game, but since i’m a bit new to actionscripting and all, I might need help. My idea is a 2d version for the hit Xbox game Halo. I’m just going to do the first level at first, and over the summer when im out of school, i might start adding levels.

These are the scripts I need:
how to make a movie clip rotate without rotating on the X/Y axis
How to swich through guns
Gravity script (jumping)
shooting script
Sheild and health script (sheild regenerates after 5 seconds)
Computer AI script ((for Grunts, ect.) Also, i want them just to walk around intill Master Cheif is spoted)
Vision script

This is just a few scripts, im also looking for Super Metroid Samus Arian sprites, Zero Mission sprites, and Custom Gun/HUD/Enemy Sprites. thanks