Have you ever joined a group for a DND 5e campaign and had problems with the group? Using Session Zero effectively can limit that.
Exhaustion in 5e is one of the most brutal conditions that are possible. It is a condition that can directly kill your character.
Looking for dnd homebrew tools to create your own campaigns? I highlight three of my favorite. Inkarnate for Maps, World Anvil for World Building, and Reroll for characters.