Replaced alternator and accidently grounded battery cables and know it wont even crank over

You skipped the 1st step
disconnect battery minus lug 1st, , rule 1st off. last on, all cars. USA.
so you blew up the fuse, or fuseable link there next or inside
the main box. PDC the main power box has huge fuses.
this is covered in the FSM. buy one, so you know the steps.
and not get hit with flying acid. (photos not pretty)
or
alldata.com RTM

if you had a voltmeter, all this would be seen now
you see voltage at battery but it dont make it past the PDC
simple cause. fuse blow.
12v xxxxxxxxfusexxxxxxxxxxx-0v
see my schematic. see 0v, bingo, fuse blown.
every time.