Off.
The pkg_create(1) application is normally used under the covers by the porting infrastructure during make(1) with the package target, and almost never by a port developer.
You've missed FAQ 15 -- or you read it and were confused -- it wasn't in your list of documents you've reviewed. There's great guidance there.
In order to "use" the ports tree, you must first obtain a ports tree that is synced to the flavor of the OS you are using. (You can only mix and match -stable and -release, as they use the same underlying libraries.)
For -release, you can download and unpack the ports tarball. For -stable, you must use cvs(1). For -current, there is a daily tarball but cvs may be more convenient.
Note: There is usually little difference between the -release and -stable ports trees; for the last several years there hasn't been sufficient resources to develop -stable ports except when there has been a security issue with some port.