The "pa" representing possession is very confusing to me. How do you say "This is NOT mine."

This is not mine.

Sa se pa pa mwen an.

or

Sa se pa pa'm nan. (contracted)

Example:
1.  This is mine.
     Sa se pa mwen an.

2.  This is not mine.
     Sa se pa pa mwen an.

3.  This is yours.
     Sa se pa ou la.

4.  This is not yours.
     Sa se pa pa ou la.

5. I'll give you mine.
   M'ap ba ou pa mwen an.

6. This is hers.
    Sa se pa li.

7. This is not hers.
    Sa se pa pa li.

8.  This book is mine.
     Sa se liv pa mwen an.

9.  This book is not mine.
     Sa se pa liv pa mwen an.

10.  This child is ours.
       Sa se pitit pa nou an.

11.  This child is not ours.
       Sa se pa pitit pa nou an.

Note:  The definite articles you see at the end of the Creole sentences (a, an, la, nan) sometimes accompany the possessive adjectives (mwen, ou, li, nou, yo).

Here are some links on the possessive adjectives:
possessive adjectives 1

Possessive adjectives 2
Possessive adjectives 3

Possessive adjectives 4

Ask me anything