In addition, know that you must include a change address UTXO in the child transaction of you are the sender. If change address UTXO is not included, you will not be able to use CPFP as the second transaction.

The miner fee still comes from part of the bitcoin you re transferring, but you must include change address UTXO (not necessarily all the bitcoin in the UTXO)

If you are the receiver, you can also spend the unconfirmed output on some wallets, like electrum.

The fee that would be paid should be a fee that can get two transactions confirmed at ones when the last fee paid has been added along.

CPFP fee= fee that can get two transactions confirmed minus the last fee paid.