Most likely its a battery problem, batteries do not like to sit.
As already mentioned get the battery charged up and checked.
A battery may appear as OK on a meter but once activated by cranking the amp draw is enough to not activate the ECU.
The quick check is making sure the fuel pump activates when key on, you will hear it hum. After a second or two, turn to crank.
There are occasion flooding happens but rarely, this is when a strong battery come in to play, you may need in that occasion to hold throttle wide open as mentioned.
Hopefully it was stored with fuel in the tank, I have seen fuel pump issues related to pressure regulator when stored with no fuel.