VPNs are primarily used to get around ISPs blocking content(more common in other countries) or hiding your IP when visiting the seedier hives of scum and villainy on the interwebs. Folks that travel frequently will use a VPN to protect themselves when using public Wi-Fi networks or utilizing remote desktop apps on their home or work computer. Some utilize a VPN at school or work if their school internet provider or employer is particularly creepy about tracking everyone’s internet use. Gamers will sometimes use VPNs to get around region locks or limits on multiple connections from the same IP.
And actually no, unless you work for the CIA or NSA(and maybe not even them), no one can get your real IP from a website you are accessing through a secure VPN. The top sites are not located in the US and don’t give out or even keep records of who accesses what - that is kinda the whole point.
Using a VPN can also lead lots of headaches when logging into sites that remember you through saved cookies or only recognized authorized IPs on their end. Amazon.com, gmail, and lots of other sites and some MMORPGs are a pain with that. “We don’t recognize this location.” Some websites outright reject all connections from known VPN IPs.
Most likely you don’t have a use for one. Your anti-virus provider is just trying to push more product. I use one, but I never said I was a role model.
FYI…some VPNs will not block identifying IPv6 information and you might still be using your ISP’s DNS while connected to the VPN. You have to be aware of these things if you want true privacy. You can check this info at http://ipleak.net. Some VPN software will temporarily disable IPv6, but if that doesn’t work you have to do it manually.