P2 is a connector. You input your step signals there.
the datasheet for the A3980 has a circuit diagram but doesn't show connections for the control pins (step, direction, ms1, ms2, SR, SLEEP, ENABLE and PFD). These are all described in the text. If you are a beginner, I would not recommend you use this chip unless you can find a design some where. It's fairly complex for a newbie.
I think you might be better off buying either a kit or a completed PCB. I don't say this as a negative but rather as my belief that you will get up and running a lot faster that way.