I assume you made your AppleID while setting up the iPhone, since it was your first iPhone? If so, you cannot disable it. All new AppleIDs for quite some time now are created with it enabled and it cannot be disabled.
Even if this was a pre-existing AppleID, if 2FA was enabled after just 2 weeks on, it is permanently on. Apple requires it for a number of Apple services accessed with your AppleID (e.g. Apple wallet &Apple pay, messages in iCloud, Home Kit, iCloud Keychain, etc).
If you explain your issue with 2FA we can perhaps help. A 2FA code is rarely required unless something is amiss. I’ve been using 2FA for years and I maybe need a code a few times per year at most.