2005 Cadillac CTS Will not start

My vehicle was placed in individual storage, it was not climate controlled but it was kept away from all the snow, wind, sun, and rain. It has been in storage for a year now plus a few days. The vehicle started once during initially being jumped. It was only running for about 4-5 seconds before being cut off. After it would no longer turn on a new battery was purchased, it still does not work. When turning the key there is a clicking but the engine does not crank. Before leaving the car in storage fuel stabilizer was put into the vehicle and upon return dry gas was put into it as well. Is the issue with the vehicle a starter or something more?