My car have been sat in our garage for just.

You don't necessarily need a new battery. Put a small charger on the old one set to a slow charge rate for a few hours. It will take up to an hour for a totally dead battery to START to take a charge. It can take that long for the acid to become conductive, then it may take a couple of hours to fully recharge. It is somewhat common for fuses to blow when a charger or new battery are connected. That's from the surge of the many computer memory circuits charging up. Just replace the blown fuses once the engine has been started.

As for the gas, diluting the old with new should be sufficient. I have an '80 Plymouth Volare and a '93 Dodge Dynasty that both have over five-year-old gas, and they both start and run fine. Seems the gas doesn't hold up so well in other parts of the country and world, but you shouldn't have any trouble with one-year-old gas, especially if you add some new to it.