I did not take calc in high school and still managed to get an A. Although the exams can be rough, if you properly go over classwork and the practice exams you should be able to not fail them. The exams and quizzes are definitely the worst part, but carefully read the syllabus and make sure you do everything else (piazza posts, webassign hw, polling questions) and you should be able to get 100%'s on that part of the grade which can really help you if you bomb some of the quizzes/exams. Overall it's definitely not an easy class especially if you have no prior experience in calc, but it's definitely doable.