That depends how well you can cram a book. Neither exam is considered overly hard. For psych, I literally just crammed the weekend before using a review book and got a 5.
Past FRQs for all exams are on the CB site. e.g.:
https://apcentral.collegeboard.org/courses/ap-calculus-ab/exam/past-exam-questions
https://apcentral.collegeboard.org/courses/ap-calculus-ab/exam
I took AP Calc before the last redesign, so I have no idea how relevant tests before 2017 are now.