Electrical Issues

I just bought a 2011 Buick Regal with the 2.4 liter engine. It was in a accident. The side impact airbags are blown and it has some front end damage. I have removed the front bumper and fenders. Underneath of the parts that I removed it looks to be in pretty good condition. My concern is when I put a new battery in the vehicle to see how the engine runs but nothing will power up. The only things I get is the check engine light on and I can't remove the key from the ignition but I can turn the key on. With the key on the dash doesn't power up and I can not used the windows or open the trunk. Where do I need to look so I can get power to the window and dash? Is the something the when the car is in a accident that I have to reset? I can not find any broken wires and I have power to the fuse in both inside and out. Thank you for taking the time to read this and hopefully you can help me out.