How do I make a Minecraft map title show only once?

Solution 1:

You can show the player on that coordinate the title and give them a score based on his location. If the player has that same score, don't show to him. It would look like something like this:

In chat, first, type in:

/scoreboard objectives add Location dummy

Then you can have in a chain of commands with the following template:

/execute as @a[...] unless score @s Location matches <LocationId> run title @s title {"text":"Great East","color":"gold"}
/execute as @a[...] run scoreboard players set @s Location <LocationId>

Simply change <LocationId> to whatever number you want and the @a[...] to your liking (you can keep on using the same as in your question). Remember to have different places with different numbers.

This way, the title will only show once, and will only appear again if you go to another place.