A VPN is a virtual private network. It can literally be understood by simply breaking down the words:
Virtual - Because instead of being physical it's virtual or artificial
Private - Because the communications between your computer and the VPN
are protected through encryption, virtual tunneling protocols, or the use of dedicated (private) connections.
Network - (obvious)
When you connect to a VPN, you're really making an encrypted (or otherwise private) connection to another device to be able to access a virtual network on that device as if you were physically connected to that network (just like a LAN). If the VPN acts as a "gateway" and is itself connected to the Internet, then it can share its Internet connection with any device connected to it. This means that when you're using the Internet on your VPN-connected device, it's really utilizing the Internet capabilities of the VPN itself (bypassing any Internet-based restrictions on the device that's connecting to the VPN, and replacing them with any possible restrictions set on the VPN itself).
Since you're relying on the VPN to give you Internet access, it will usually degrade not only your ping time, but also your bandwidth. Also you will have to trust that VPN not to perform Man-in-the-Middle type attacks on your Internet, and to not attempt to access your physical LAN or LAN-connected devices. So yes, there is a degree of risk involved in that aspect.
As for the legalities, it could very well be illegal and more than likely is illegal to bypass any kinds of restrictions that your government had set in place. However in order to find out for sure I would recommend doing your own research on that subject. My advice is, just don't do it. Wait 48 hours and see what happens.