The Lexus gx470 battery ran flat after prolong.

The lexus gx470 battery ran flat after prolong use playing music loud with doors open in the morning without first starting and running the engine. The car refused to start thereafter. When the battery was taken for recharging and brought back, the engine started but not running properly and automatic gear refused to engage. The gear lever moves through the drives but does not select or engage the engine to move the car. An indicator(A/T P) is showing on the dashboard screen. Help now please.