Hello Rowena,
You are very Welcome! You may want to wait to take the certification exam. Penn Foster will pay for your exam, the practice exam, and provide you a study guide for the exam when you have successfully completed the course. However, you could use the time to study for the exam. Additionally having hands on experience (the externship) will also help you prepare for that exam.
Penn Foster will not process the graduation documents/resources until you have successfully graduated from the course.
Please contact me again if you have additional questions.
Best,
Kathy