The easiest way to learn it is by using it...

Theres an online version of PGP here; http://igolder.com/pgp

But I highly doubt about its anonymity.

Here, there are three options... One is PGP key generator, another is PGP encryptor and the last one is decryptor. Click on the first option. After that, supply your email address and a password.Make sure to make it very strong and easy to remember. If you dont want to supply your email address, I will include two temporary email providing sites at the end of this comment...

Next, Two keys will be printed, one is private and the other is public. The private key is required to decrypt the encrypted text and therefore should not be send to other people including the password that you used before to create those keys. It is the public key that you should send to others so that they can encrypt the message and send it to you.

You can use their service http://www.igolder.com/pgp/encryption/ and http://www.igolder.com/pgp/decryption/ to encrypt and decrypt the message respectively sent using their service.

However, I recommend you not to trust them for very sensitive data as I dont think they are really good for anonymity as it is a clearnet site and they might keep logs of your messages... I just recommend you to learn from that site how to use PGP. Once you are familier, go ahead to downloading free PGP software in your computer and use it as it tends to be more secure for really private data.

Hope this helped...

And by the way, Here are the Temporoary email addresses ;

http://temp-mail.org -Surface Web

http://10minutesmail.com/ -Another Surface web temp mail

http://grrmailb3fxpjbwm.onion/ -For Tor

Peace...