So, I was thinking that a basic understanding of cryptography is very useful for every anon and free speech lover, particularly if this site goes down or similar.
I will not teach you directly, but give you some challenges and if you understand the cipher you just will need to answer using that cipher to encrypt your messages.

Challenge 1: Extremely Easy

This will be the encryption for normal communication in case of need.

Understand the encryption rule by decoding this message:

Wkh zhvw qhhgv vpduw phq wr ixqfwlrq, dqg wkh lpsruwdqfh ri wklv zloo jurz hyhub bhdu wkdw vhsdudwhv xv iurp wkh lqfrplqj froodsvh. Uhqdlvvdqfh phq duh qhhghg, wkdw kdyh qr ihdu ri iljkwlqj iru wuxwk eb dqb phdqv qhfhvvdub.
Wkh uxoh iru rxu edvlf fdhvdu'v flskhu lv wr dgg ru vxewudfw d qxpehu htxdo wr wkh fxuuhqw gdb. Xvh dq dxwrpdwlf wrro, lw'v ehwwhu.

don't write the decoded message directly or brainlets will have it easier to understand the rule. Here I wrote it explicitely but later I won't.

More difficult challenges will come later.