If I am graduating this semester, how will S/U affect me in a class I need to pass to graduate? How will it affect my GPA?

Remember that S/U grades do not change your GPA. They only reflect credit earned or not earned. For instance, if you are in your last semester and need specific letter grades to get or keep your GPA above 3.0, then the S/U grade will not be a good choice for you. If your GPA is already above 3.0 and you just need the credits to complete your degree, then the S/U grade might be something to consider. It is important to understand and review your degree audit and situation with your faculty advisor and/or graduate program director so that you can make an informed choice.