If you've got the NordVPN icon in the dock, then you can right click and select Options/Open at Login. This may be what you want. If not, then contact NordVPN, who should be able to help you.
As for the anti VPN comments on here, I think I need to point out that VPNs are used with no problems on Linux, Android, and Windows, so why not on macOS? Linux is based on a reverse engineered version of UNIX, Android is based on Linux, and macOS is based on a fork of UNIX called Darwin. The people who run the VPNs have access to your logs, but they don't care, although your ISP and government do care.
BTW, did you know that Apple TV+ can help you learn another language? Apple TV+ videos are usually available with the soundtrack in English, French, German, Italian, Japanese, Portuguese, Russian, and Spanish. Not only that, but the French is available in French and Canadian versions, and the Spanish is available in Spanish and Latin American versions. Subtitles are available in English, all the languages I've just mentioned, and some other languages, including Chinese, Dutch, and Ukrainian. This facility is available on macOS, but not on the Apple TV+ app on Roku TV. I haven't tried it on iOS.
[Edited by Moderator]