Each game can stand on its own. Nintendo is well aware that its audience will always include children playing their first Zelda game on their first console.

If any of the games refer back to a previous one, it will almost always be Ocarina of Time. OoT depicts the origin story of the series’ main villain, so the boss fight at the end of that game marks the “Year Zero” for the series kind of the way the Battle of Yavin does in the Star Wars fandom.

Because Ocarina of Time involves time travel, it actually forks the timeline into three paths: Link is defeated, Link defeats Ganon and the timeline continues from there, Link travels back in time to prevent Ganon from rising to power in the first place. Later a fourth branch was established: Prequels, set before the events of OoT.

At least one game is a fever dream, at least two games take place in other, faraway kingdoms, at least one game can be interpreted as a fever dream or a faraway kingdom, and then Breath of the Wild and Tears of the Kingdom seem to be a reboot of the series because ToTK retells OoT’s story and retells it wrong.