How do you know which resources to trust? | Forum

Hi fellow Uni students i need your suggestions, I am studying for my final exams and my professor just told us that the textbook is not enough. He said we need to be reading articles and case studies to get a good grade. Now I am freaking out because I have no idea where to even start looking. I have been searching for a good assignment website for students, but there are so many and I do not know which ones are legit. I am so scared of using a bad source and getting in trouble. Does anyone have any recommendations for good, free academic websites?