Assuming you would like tips on how to open a gas cap on a RAV4:
If your RAV4 was built in 2006 or later, there is a quick release button located under the lip of the gas cap. To open, press down on the button and turn the gas cap counterclockwise.
If your RAV4 was built before 2006, there is not a quick release button. To open the gas cap, insert your key into the lock and turn it counterclockwise.