As someone who’s a complete beginner to crypto, can someone please help me make this Monero payment for Mullvad VPN?

That’s unfortunately the easiest way to do it. As of now, there is not really an anonymous way to buy Monero itself , but it will be anonymous what you buy with Monero.

See also the discussion here: Cake Wallet: Monero via DFX requires KYC now. Alternatives?