The nice thing about AT&T Park is the area. There are tons of restaurants and bars in the area so finding a fun spot before and after the game should not be a problem.
Walking around the stadium, you should always have a great view. You can literally walk around the whole thing from the upper levels and still see the game very well. And there is lots to see as you walk around.
I would also recommend taking the stadium tour prior to your game. Maybe the day before or something. You will get a good layout of the land.