[0] CTF for beginners

The Capture the Flag or CTF competition format is used in paintball, among role-players, in computer games and in information security.
The goal of each stage is to find the flag. In the context of this CTF, the flags are links (example below).
Ready to start? 2hash.ru/ctf/a8802331696f7a2f3ab7fe861206ee9c