I would strongly suggest you
Don't get Halo 4. It's campaign is generic, and the final "Plot twist/end of story twist/final mission" makes no sense.
The multiplayer is average at best, and one of the mains reasons I got Halo 4 (A multiplayer gamemode named "Dominion" which was actually pretty good) got removed fast.
There's one or two *Average* new gamemods, and the rest aren't really done as well. Get Reach for Multiplayer. Get anniversary addition to start off with your plotline. They also have a RTS halo game (Halo wars, which I absolutely adore. In fact, It made me re-set up my xbox 360 just to Play Halo Wars. Great campaign, tons of units, and 6 different leaders to choose in Skirmish/multiplayer).
You can also get a Top-Down shooter Halo Game, (Spartan Assault) on steam for 5 dollers. I'd say it's worth the price.
But yeah, just getting Started in Halo, I'd highly recommend Anniversary addition/halo 1, or/and halo 3.
Of course if you're a nerd like me you could get the first book, "Fall of Reach". Or the technical first book, "Contact Harvest".
Below is seen my entire (Physical, lol) Halo Collection.
