There are many good free VPNs. Free VPNs are a great thing, but there is always a reason why it's something for free. I personally use several VPNs. Although, some are not completely free.
One of them is ExpressVPN. Even though it is not completely free, a 30-day money back guarantee makes Express an excellent choice for those who are just familiar with VPN technology, and want to have a good start with a good service. The only disadvantage is that there is no option for a completely free service.
The other one I use is TunnelBear. TunnelBear is probably the easiest to use, although free subscribers each month are limited to only 500 MB of traffic.
The third one I use is Hide Me. It has 28 servers distributed in 22 countries and is quite popular. In my opinion, it has a decent connection speed. The only disadvantage may be that the free version is limited to 3 locations.
To get the best possible encryption and connection speeds, I would recommend using a paid VPN service.