First, a quick introduction to nethackcoin:
This game is hard
but worth it
Also it is not very user friendly, here are some links and info that will help you:
A proper intro to nethack:
A list of all the commands you can change them, like the movement can be your numerical pad if you want
The nethack wiki it is almost impossible to finish the game without being spoiled.
The nethack subreddit
You can also go to irc.libera.chat with your favorite irc client, on the channel #nethack if you want help
nethackcoin is also playable with ssh (the best way) with any ssh client juste write "ssh firstname.lastname@example.org" on a terminal, you also gonna have to remove "OPTIONS=vt_tiledata" from your options file in the dgamelaunch menu.
You can also play nethack (not nethackcoin) on android
And if you want an introduction to bitcoin, here is a proper video: