How much story would I have missed out on having only started with Halo 4? Would you recommend Halo 4 to a beginner such as myself? It's a shame that I waited this long to play this exclusive. I never really knew anything about it, therefore I never really gave it a chance. Same for Gears of War, fwiw.
Go ahead. You might as well go and Buy Halo 3 as it probably cost 10$. Playing that will shed some light on Halo's story. I guess your in school so check you library for any Halo novels as my middle school had them. Check your town library if you want.