My macbook air will not automatically connect to the internet now, we had to create a new router name, and everytime I get on, I need to find and select it, help me stop this, it's annoying

We had to create a new name for our internet connection w time warner cable. now our macbook air (MINE ONLY) will not select this unless I click on it. It used to be set up that it automatically selected it. I've tried everything, nothing works. I lock it, doesn't matter, it just goes back to "no network selected." It's driving me crazy. Oh, and the printer won't connect now either. UGH.