If you want the simplest VPN service that is free, super simple to set up, and provided by a well-known mainstream company, there is no service that satisfies all the criteria other than Cloudflare. Its offering is called WARP. You can go to its website at www.cloudflare.com, search for WARP, download and install its WARP program. You don't even need to provide it any names. Once installed, you would simply turn on the WARP service. This will create a VPN tunnel between your computer and its many relay servers on the Internet. When you browse the Internet under this WARP tunnel, the websites you visit see the Cloudflare's relay server instead of your actual computer's network. That's it. Because of its simplicity, this WARP service has one big disadvantage. You cannot control the "exit server" on Cloudflare end. So if you want the website you visit to think you are from a particular country, this is not possible.
Cloudflare offers much more than this if you want to dig deeper with its Zero Trust network. With this, you can have two computers at two different geographical locations join a virtual network using Cloudflare as the middleman. This service does require 2 things: you have a custom domain such as yourdomain.com and that you use Cloudflare as your domain's DNS server.