First thing to do is get it charged up, and then park it. Disconnect the battery ground. In reduced light, put your 12V test lamp from the battery NEG post to a good ground, like the engine Make sure everything is off, dome, trunk, etc, and see if you can see a light
If you can, you have a "big" drain
If not, leave the battery disconnected overnight and see if it will start
Could be either. Otherwise, charge it up, take it to someone who knows what they are doing and has a "carbon pile" battery load tester.