Wont turn over is not firing it makes no sound at all

I have a 1996 chevy blazer, when I try to start it the lights and the radio will come on but it wont turn over is not fireing it makes no sound at all, I replaced the starter that wasnt it because its still doing the same thing, I was thinking it might be the ignition modular or the distributor, if its one of those could I do it myself and how would I go about doing that I cant really afford to pay a mechanic thank you so much for your help!