Old fashioned idea, and something that works best in the dark.
Turn your headlights on (and radio, blowers, heated screens if you fancy) then try to start. If the headlights dim (and your radio etc. die) then you know that it is trying to start but either there's not enough battery power or the starter / solenoid is not functioning.
If the headlights don't change then the car is not even trying to start and you'll be starting with EKA code and, if necessary, onward into the electronics.
Remember if you end up with jump leads be careful to connect and disconnect them properly otherwise you could add to your problems.