To be eligible for the PMP credential, you need to meet certain educational and professional experience requirements. All project management experience must have been accrued within the last eight consecutive years prior to your application submission. You need to have experience in all five process groups across all your projects. However, this does not mean you should have had experience as a Project Manager per say. Many professionals who have experience in leading and directing projects, not necessarily in a managerial role, but even in a functional role are eligible. For example, people from marketing, programming, event management, etc. also take up the PMP exam and attain it.
The PMP exam is comprised of 200 multiple-choice questions. Out of these 200 questions, 25 questions are pretest questions. You will find a lot of information on what these are and why they are placed, but from the point of passing the exam, this is not needed. Knowing that you have 4 hrs to answer 200 questions is sufficient for you to get ready for it.