What is the first part to upgrade on a Norinco 1911 Government model?
And what would you upgrade it with?
My recommendation is DON'T CHANGE ANYTHING; BUY AMMO INSTEAD. Shoot the gun and get a feel for what you like and don't like about it. Make yourself a promise not to change out any parts (except maybe grips) until you have at least a thousand rounds through the gun, maybe even two thousand. Make mental notes or even take notes. You will have a much better appreciation of the changes you do end up making when you have intimate knowledge of what you have changed. You may also find that you don't want to change as much as you originally thought you would...
While you are putting the first thousand rounds through it, be sure to spend plenty of time at home researching what parts are available and what they do. That way when you encounter things you do not like about your gun, you will have an idea of what to do about it. Scour forums such as CGN, 1911forum.com, m1911.org and 10-8forums.com for information. They are all great forums that contain a ton of good info.
Completely tear your 1911 down (right down) and put it all back together again; a few times. Get familiar with each and every component that makes up your 1911, right down to the smallest pin. Become one with your 1911.

Only then can you begin to start changing out parts and components. It is the Tao of the 1911...
Or, just flip through the Brownells catalog and pick out whichever parts look cool to you and order them.

Either way, it's all good...
EDITED TO ADD:
All of that being said, go out any buy yourself some quality aftermarket magazines such as those offered form Chip McCormick, Wilson Tactical or Tripp Research. Quality mags are essential to to reliable operation of a 1911 and the good ones actually don't cost a lot more than the lesser quality ones.