How can I turn off VPN on my iPad?

If you're referring to Private Relay, see:

Set up iCloud Private Relay on all your devices - Apple Support

Otherwise, as Idris indicated, any VPN would have come from a third-party developer, so you'll need to find uninstallation directions from that developer.

Regards.

No, it's not possible for anyone here in this user-to-user forum to turn anything off on your computer. As iPads don't come with a VPN, you should be able to turn your VPN off "for good" by deleting the VPN app.