Re: First black rifle..
Congrats on the new toy! They're great rifles and I'm sure you'll have a ball with it once it's up and running. As to the accuracy, that's a difficult question since there's so many variables involved. As to the AR system/design, yes, they're extremely accurate. Easily the most accurate Service Rifle the US military has ever adopted. Sub MOA groups are downright boring in a properly built AR, and those that will break 1/2 MOA on a regular basis are pretty common. Some will do better. The question comes in as to the quality of the barrel, how well the gas tube's fitted, chamber dimensions and type, and how it's throated. Like I siad, lots of variables.
There is another way to find out; go shoot it. With decent ammo, I doubt that you'll have any problems getting into the MOA neighborhood, give or take a little. Just remember to avoid the FMJ surplus stuff, as it's generally 2-3 MOA stuff out of a really good rifle. Just wasn't meant for any better precision than this. With good match bullets and proper reloading, you'll do better than this easily. And yes, the 1x9" is perfectly adequate for the 68-69 grain bullets, no problem.