Q: 95 blazer s10 wont crank or start

Was headed to lunch today, and my blazer wouldnt crank. Ive had minor issues over th last week when starting it up. Sometimes it takes a second to crank, sometimes it cranks instantly (almost too quick), and then again at times its normal. Well i blamed it not cranking on the battery, due to the recent weather. So i went and bought a new battery, installed it, and boom, no difference. The vehicle has power(lights, radio, ect.) But will not crank or turn over. Tapped on the starter, tried starting it in different gears, checked the fuse panel inside, just about everything i could think of with my little knowledge. No click, no tick, nothing. Vehicle was slightly low on oil, but that shouldnt affect it starting should it? Also installed a radio a couple wks ago. Left the knee panels loose until the dash kit came in the mail to complete install. But everything worked just fine until lunch. Could it be the neutral safety switch or something minor? Or do i have a bigger issue to worry about

My car has 142000 miles.
My car has an automatic transmission.