Do I need to get Quicktime Pro.
It depends on what you want to do. QT Pro (a.k.a. QT 7 Pro) allows you to access the older 32-bit editing features contained in the current Snow Leopard dual 32/64 structure and accessible via QT v7.6.3 software. If you plan to edit files at the individual track level, layer audio and video content (create picture-in-picture, picture-with-picture, picture masks, etc.), then you may need it if you don't have other, more expensive alternatives available. On the other hand, if all you want to do is watch movies, then you wouldn't need it.
I don't know if I even have Quicktime Pro.
You have to purchase and enter a "Pro" registration key. So if you haven't done this, you don't have QT 7 Pro.
Is Quicktime Player different then Quicktime Pro.
The actually software is the same. All "Pro" does is allow you to access additional QT features already embedded in the system. Many of these features can be accessed from other Apple applications like iMovie, iTunes, GarageBand, and third-party applications like MPEG Streamclip (free).
If so how do I upgrade?
Go to the online Apple Store and purchase the QT 7 "Pro" registration key.