It's hardly the cars fault though ?

And it is pointless doing anything unless you know you have a fully charged battery


If the ignition lights all come on the dash as normal, then there should be enough power that you would hear the fuel pump prime.
But by connecting the battery wrong, all sorts of damage could have been caused in the vehicle electrics.

How much is the car worth ? And are there any decent auto-sparks near you ?

And are you sure the vehicle isnt immobilised either by a factory system or aftermarket, either of which could have been fried too.