If your check engine light has come on first check to make sure your gas cap is on tight and/or not broken or damaged in anyway.
If your gas cap doesn't seal it messes with the engines computer and can cause your check engine light to come on.
If your gas cap is not broken or is on tight then you should take your car to autozone or another auto parts store or even a mechanic to get the check engine light diagnosed.
It could be something simple and not as serious or it could be something major.
Although the check engine light doesn't really mean something urgent needs checked it's a good idea to get the check engine light checked out as soon as you can.