Won't start after battery ran down.

[bremsstrahlung]

Hi all - I'm new here, and purchased a 2013 impreza two months ago. No start - I believed the battery was dead because my lights had been left on. Attempts to jump start were unsuccessful. Will not crank, doesn't make a sound at all. Battery in key fob tested okay and all fuses under the left dashboard tested good as well. I left it connected to the truck via the cables for a good long time and now the battery tests fully charged. I can turn on the head lights, yet the radio won't play, the windows won't go up and down, and curiously, the car won't shift out of park and the brake pedal has become very stiff. Am I missing something? These "modern" cars confuse me so! The newest car I've ever driven is 18 years old
P.S. the panic button won't work on the key fob, that is why we initially tested the battery. Any suggestions are appreciated - thank you in advance.