Pen Spin guide
So here I gathered the most commonly used tricks and sorted them by level of difficultness. You can refer to this list to have an idea of which pen spinning level you are on at a moment and where to move next.
As well, you can refer to this video, which may help you to decide order of trick learning:
You can consider yourself at a certain level, if you can do at least 4 tricks of this level and about 80% of a previous level.
Note, that you don't become a PRO after reaching 5th level. You are at level 5, and tricks you can do are PRO - not you:)