hi, I'm a newby in BSD/Linux, but I tried GhostBSD in live and I really liked it.
I would need to use a vpn and I would like to know if by installing GhostBSD I can install Mullvad VPN for which I already pay a subscription.
In case it is not possible I would like to know the other possibilities.

Looks like it can be used with both OpenVPN and WireGuard.

Linux instruction for OpenVPN https://mullvad.net/en/help/linux-openvpn-installation/
Linux instruction for WireGuard https://mullvad.net/en/help/wireguard-and-mullvad-vpn/

Here is some FreeBSD forums related thread https://www.google.com/search?q=mullvad ... 8&bih=1077

Here is some FreeBSD Reddit related thread https://www.google.com/search?q=mullvad ... 8&bih=1077

Thank you for the quick reply.

As a solution it seems rather complicated,
I was wondering if there were any alternatives with a gui and without necessarily having to use the terminal.

I also ask a probably silly question: Could the Windows version of Mullvad work using wine?

I think that almost every VPN works with Linux, so I think that you won't have any problems with installing and configuring VPN. However, when I used Linux, I did not use VPN, mostly I used proxy servers. And mostly they were proxies from this site https://soax.com/seo-monitoring, because I could not find other high-quality proxies. But since you use VPN, I think you don't want to hear about proxies, but I think it's more expedient to use proxies anyway, since they don't consume a lot of Internet traffic.