You have to check the state of charge in the battery even if it is new.
You may have a charging problem and the battery is discharged do to a problem with the alternator.
Another thing that needs to be checked are the fuses (for the charging system) and the battery connections.
First thing to try is a jump start if the car starts with a jump the starter is probably good.
Once you get the engine running check the voltage at the battery with a volt meter,(engine running) it should be over 13.5 volts. If it is not check belt tension and alternator connections
If it does not start with a jump check the battery connections at the starter the ground points (at engine and the body) and the connections at the battery posts.If all is good and the battery checks out suspect the starter or starter relay-solenoid.
