1995 Chevrolet Monte Carlo Fuel problem or ignition switch?

I hope you can help us, as we just bought this car and we spent every dime we had on it, so taking it to a mechanic is out of the question. It's a 1995 Chevy Monte Carlo with a 3.1 and approx. 129,000 miles, however that's questionable because the odometer isn't working properly either. But the big problem we have right now is this. For the last week and a half or so, (we bought the car January 28th) when you turn the key sometimes it would sputter a bit before turning completely over. Then after you get out on the road it jerks and chokes like it wants to die. Sometimes it will, but not always. When it does die it starts back up, but it won't take long for it to start cutting out again. We live in a rural area but close to town, so we haven't been traveling far since we got the car, (mainly because we had to replace the turn signal switch the day after we bought it along with 4 tires), so we were hoping that a clogged fuel filter or maybe dirty injectors would be the problem and we replaced the filter and dumped in some sea-foam with our fingers crossed. This morning we started the car up and once again it hesitated on starting, and we wasn't maybe 4 miles from home when it started cutting out and dying. We stopped at a gas station to turn around and go back when it died for good and now it will not turn over at all. It is acting like it's not getting fuel, maybe a fuel pump or bad injectors, but from what I have read it could also be the ignition switch. My question is this. How can my husband test to see which one it is, or if it's either one of these problems at all, with out taking it to a garage, because as I started off with, we're broke. Thank you in advance.