Laila, it's natural that you and your father are very scared right now. We've all been there. The possibility of a cancer diagnosis can hit like a ton of bricks.
If he's a computer kind of guy, you might ask him to browse around on this site. As you'll notice, you can visit various pages and look at the different threads going a long way back (442 pages showing on my computer right now). You can also use the search function to find discussions of particular topics (e.g., "biopsy"). I would hope he might find it reassuring that so many effective treatments are available for prostate cancer found early.
And, please emphasize again that it's still only a "possibility" that he has prostate cancer. The biopsy should either rule it in or rule it out.
I hope he also realizes what a lucky Dad he is to have someone as concerned for his well-being as you obviously are. Please keep in touch and let us know how things are going, and if he wants to start posting here himself, we'd love to hear from him.