I agree with the posts above. If you go to a bookstore or a good public library, you will find pcat exams. If you attempt a diagnostic exam and bomb it or hate the format, seek a professional opinion because this test will challenge you and maybe pharmacy is not what you want to do.
If you decide to continue, start early, work all types of questions for biology, work chem problems, skim through micro and physiology, review your math equations, go through some reading comprehension passages, and time yourself accordingly.