I can recommend Tor browser. It's free and so you can use it without cost, but some sites block access via Tor and Vpn so, you should immediately decide for what purpose you will use it. In General, remember that 100% anonymity network does not exist.
If you want something free that hides your IP look no further than Tor. However many channels are being followed by security agencies. They go as far as to set up tor nodes and channels of their own - like honeypots, or at least so I've heard. It's still a much safer option in my opinion than a free VPN like hidemyass which most certainly keeps logs and will rat you out if needed. Another bonus of Tor is it's very easy to use.
For a good VPN service I go to Nord. Great client, very comfortable, with a world map where you pick what IP you want, and there's plenty of choice. Also the connection speed doesn't drop as significantly as with free VPNs I've used.