In what case would you use a PGP key?
In a case in which I want to encrypt a message that can be decrypted by both parties. From the one that encrypts it AND from the one that has the key to decrypt it. That's why it's called "symmetrical" encryption, because it's showing symmetry on an axis.
On the other hand, on
ECIES, the message can be read only from the one that has the private key to decrypt it. Hence, "asymmetrical".
You can encrypt symmetrically with PGP by installing
gpg4win. For a beginner, the GUI of kleopatra is good enough to make gpg understandable.
After you generate a pair of keys, here's how you can encrypt a message:
(On the second dropdown you can choose the recipient after he/she's given you a public key)
If ECIES is unknown to you,
which is most probably, you'll find out that electrum allows you to encrypt that way: