Checking your oil each time you visit a gas station is a sound practice, and can keep your car running without trouble. If a check oil light comes on in your message center, you need to check the engine oil level immediately. To check the oil on a Toyota Highlander you just have to know how to read a dipstick.
This process does not require tools.
If you feel any tools are required, feel free to update this article.
Read the Oil Dipstick
Park your Toyota Highlander on a level surface and wait a few minutes, but no more. The oil must be warm to produce accurate readings.