Pathos: Nethack Codex

There are various races, jobs, and traits, allowing for countless combinations. While race doesn't matter much, I recommend the Samurai job for beginners. It has top-tier magic aptitude and melee combat capabilities. With a bit of leveling, you can get the Haste trait and slice through everything. However, be careful of baby dragons among the early mobs; you could easily get a game over.