Grand Prix wont start

Hi guys, my 95 grand prix se 6 cyl sometimes wont start, it makes a click but nothing, disconnected battery cable(+) once, connected it back and started, but last time that did :mrgreen: n't work, had to turn the key on several times and finaly did start, I think the ignition switch its faulty, if so, can it be replaced with a regular auto parts store switch or have to go to the dealership, also the remote(doors)opens only the driver side door.I tried to install a factory(original) radio and culdn't and I been having this problem ever since(remote).I really apreciate your help.