Well there are a few kinds of VPN: one that you run on your router or raspberry pi or whatever to allow you to access your files on your own network server securely from a remote location, a kind of personal cloud, you might use a protocol like Open Vpn or Wireguard.
You can also get a paid or free vpn services that mostly prevents your ISP from seeing what you are accessing (but not how much), and also hides your origin and identity from all but your vpn service provider (depends on the records they keep) like Proton VPN or NordVPN.
It depends what you want to do.
Regards