We understand package comes with 2 licenses, are they refer to site license or user license?
You have posted in the wrong forum. This forum is the "Community Project" which is under an open-source GPLv2 license, which allows you to use an unlimited number of users.
You are clearly referring to the "OpenVPN Access Server" product, which is a closed-source, non-free, non-GPL product that is licensed and sold by "OpenVPN Technologies Inc."
Should you wish to use the GPLv2 product that has absolutely no limit on the number of users, please see the
OpenVPN download page here. The GPLv2 OpenVPN product is free to use within the definition of the GPLv2, which basically means you can't link non-GPL code against it or sell it as your own. Please consult the GPLv2 license for full details.
If you wish to learn about "Access Server", the commercial product, please post in the proper forums section or contact the sales team.