You can try turning your engine by hand

Put your car in park or neutral and chock the wheels before turning the engine by hand

Pay attention to your gauges and dash lights while driving

Obviously this is easier to do on a smaller engine than on a big or small-block V8. If the engine turns, your problem is likely with the fuel or ignition systems. If you can't turn the engine with tools or by hand, it's possibly time to find a clean rag to weep into, as your engine is seized.

Should you decide to have your engine rebuilt or replace it with a crate engine, what can you do in the future to make sure this doesn't happen again? Engine seizures are usually caused by either insufficient lubrication or overheating, both of which will damage critical internal components. The simplest thing you can do is to change your oil and filter regularly, and make sure your cooling system is filled and working properly. 

If you're driving and the temperature gauge reads higher than normal, you can turn on the cabin heater to pull excess heat from the engine compartment. If your oil pressure light comes on, pull over immediately and have your car towed to a shop. Low oil pressure can be a sign of a faulty oil pump or even sometimes just an indication that your oil level is very low. Overheating can happen when your thermostat isn't opening at the right temperature, the radiator or cooling passages are clogged, or the fan or water pump belts are too loose.