You've been sitting in your car, and nothing you do will get it started.
Before we pop the hood and start messing around and getting dirty lets check if there's any gasoline in the tank.
If you've checked the gas level and your car still wont start, it might be because your battery is dead. Car batteries are usually easily accessible and are an easy fix.
Now if your car has a sufficient amount of gas and the battery still has juice, then it might be time for an oil change.
If your car passes all of the previous tests then a leaky distributor cap might be the problem.