Look at the tip of the dipstick. You will see a little bit of oil on the end of it. This tells you how much oil is in your car. You want the oil level to fall in between the two indicator lines on the stick. If the oil is below the lines, add a little bit of oil by unscrewing the oil filler cap and pouring it in. If you add oil, check the oil level again with the dipstick to make sure you added enough.

You also want to look at the color of the oil. If it's turning black, it's time to get it changed.