The IB published a guide to compatible calculators:
Being familiar with the basic calculator functions and a knowing a few simple tricks is an essential part of answering questions and checking your answers quickly.Â
Speaking of simple tricks, the video on the right shows you how to store a variable on a TI-84 calculator.
When you take your exam, proctors will give very specific instructions according to a script that I have attached below.
Here are past exam papers. You can look for example problems that you would like to work on for a specific topic, or just use them to look over the formatting of exams. Obviously, these will be useful for revising for final exams, but be aware that most of these are from the previous syllabus.