Wouldn't use a free VPN for torrenting because most of them keep logs on users. If you're not paying for anything, you are the product.
There if you want to subscribe to a VPN provider there are
plenty of lists out there comparing the various VPNs.
Some notable ones are
PIA
Cyberghost
Windscribe
PureVPN
ExpressVPN
All of them have specific VPN servers for torrenting, which basically means that their servers are in countries that have strict privacy laws that make it harder for the government to compel them to release information regarding user data. Most of them also keep no logs on users so even if they are required to, there is no information they can provide to the government.