You can't. Halo isn't COD. Halo is about giving all players a fair chance to win, and not giving people who have played more better items. In Halo, everybody starts out with the same weapon, so unlike COD, it comes down to skill and not perks, killstreaks or better guns.

theres no way that would be awful halo isnt cod and never will be

Yep, it's true. You can't pick things like a Sniper Rifle and Rocket Launcher to start out with, it's still kind of balanced out. Check out this thread below and scroll down to see all the things in Halo 4!
Forums/t=2027005/all-halo-4-halo-...12-us.html

I'm pretty sure you can edit loadouts and stuff

Yes you will be able to customize your own loadouts. I don't think you'll be able to spawn with power weapons like a Sniper Rifle or Rocket Launcher though.

I pretty sure I heard you can pick a primary and secondary weapon, along with an armor ability and perk. The weapons won't include power weapons though. Those will either spawn randomly (note I said randomly) on the map or from ordinance drop, which is from getting so many points in the new game mode called infinity slayer. Some of the weapons are the BR, carbine, DMR, assault rife, some type of plasma rifle (forgot the name), and potentially others.

That would be cool but i dont want it too turn out to be like cod in anyway lol

Yea you can theres just no power weapons its basically set up so that people dont get pissed that they have to play assualt rifle start and they can just pick the BR/Carbine/Alien Assult rifle/ or regular assulat rifle

its basically so that you dont get skrewed over by dumb kids choices and so people like me can start with the BR 24/7

Yes this is true. 343i is trying to balance everything in the loadouts as much as possible though so that the game is still a game of skill, not who was the best loadout. You can chose a Primary Weapon (AR, BR, DMR, Covie Carbine, Storm Rifle), Secondary Weapon (Plasma Pistol, Magnum), Armor Ability, Tactical Package ( more info at halo.xbox.com or xbox.com/halo) and a Support Upgrade (more info at halo.xbox.com or xbox.com/halo) The Tactical Package and Support Upgrades are modifications you can use, they are sort of like perks but don't give you a gamebreaking advantage and people will find combinations that work for the map and playstyle they use. You might also want to change modifications according to what gametype you are playing.