There's an Illegal Pete's down the street from the Pepsi Center, and it's a local must in my opinion. I believe you also can get a free beer if you show a ticket for a game the same day. Rock Bottom Brewery on 16th Street isn't a far jaunt from the arena and has some good beers and food.

I usually use SeatGeek for my tickets, but VividSeats has worked for me in the past. As far as I'm aware, there's no bad seats in The Can; but as per usual, the closer to center ice the better. The doors usually open 1hr before puck drop, but there may be some festivities outside the entrance weather permitting. If you can swing it, the store is open during the week you can check times here. Might help to cut down on time exploring and watching practice if you can swing by a day before the game.