electrical problem help!!!

i just want to say thanks for all the help i've gotten so far... i've got a 69 firebird and i recently put a new alternator on it and didnt tighten it down until i tested it and today i tightened it down and accidently hit the battery wire to the alternator itself and it sparked wow i didnt thinkin anything about it until i got in the car thats when i found out that it has no power to anything the car wont turn over and nothing will come on mabye its a fuse???? so if someone could help i'd appreciate it

Look for a small silver box with three or four wires going to it.its on the fender,core support,or firewall.Most early chevys have this little box and when they blow out,nothing works.