It depends. If you’re using Windows or iMac or a tablet/phone, use the settings/control panel to set up a new vpn. You can visit YouTube and search your device’s name and also ‘vpn’ and see tutorials.
If you’re using a router, configure your router’s VPN client.
There is no software provided by this service. Too costly to develop and buggy.
It is unlimited at times when there is no load; otherwise it will drop to less than 5 Mbps and you can get 480p Netflix. Otherwise it can do 1080p or higher, depending on server load. See the web site for more information.