A '94 Cavalier that's lasted 260k miles? I'd say have it bronze plated or donate it to a museum since it’s only on of a handful that has ever survived that long.
With that many miles, it could be any number of things, as dodge man pointed out. You didn’t mention if the engine turns over when you try to start it or not, so I’ll assume it does. You also didn’t mention if it pops, drags, or spins excessively fast when trying to start it, so I’ll also assume the timing belt didn’t break (although I doubt it’s the original one with those miles).
You need to check to see if you’re getting spark and fuel first to help narrow down the problem. If you’re getting both, then start looking at the timing, as air, fuel, spark and timing are the four things an engine needs to run.
If you have spark and no fuel, then test the fuel pump.
If you have no spark… it could be anything in the ignition system.
One more problem to watch out for in the future is overheating and warping the head. The center head bolt doesn’t bottom out, but goes into a water passage. If the head has to be pulled at any time, and the lower threads have rusted, you can pretty much consider the head trash since there’s not enough clearance to get anything other than a thin wall socket on the bolt. The socket will break every time before the bolt does, and a torch will melt the head before it cuts the bolt.