I just put a brand new battery in and put in.

I just put a brand new battery in and put in backwards, it blew a fuse under the hood and the guy at the auto parts store said the fuse was related to the alternator. After replacing the fuse the truck still wont start. It trys but nothing. Could it be another fuse, could a new battery be dead? I would really appreciate some ideas as to what I can do about it. I look forward to hearing from you. Thanks