I have the saved key and have absolutely no idea what to do with.
What kind of key do you have?
- Private key of your Bitcoin?
- Key of your 2FA?
For [1], simply import the private key into a non-custodial wallet, such as
Electrum]/url] or [url=https://bitcoincore.org/en/download/]Bitcoin CoreHowever, i have seen that one is allowed to have more than one 2fa attached to an account. Can i attach fresh 2fa (i.e Last Pass Authenticator?)
You will be asked 2FA 6 numbers before you can disable your current 2FA and set up a new one.
and enter the private key that way?
If what you ask is about a Bitcoin wallet with 2FA, you can simply import the private key into a new wallet, in that case, you won't need to enter 2FA code just to get access to that wallet.