English:

An idea occured to me for breaking those language barriers that are in the maps, as simple as a command "scoreboard".
It consists of putting a number to each language, in this case;
"1" = English
"2" = Spanish
(In my tests I had problems using the number 0)
To form this alone we would have to put the command:

/scoreboard objectives add language dummy

Later, to make a system in which the player can change the value from "1" to "2" or vice versa, corresponding to his language, such as, for example, a button that says English and executes the command:

/scoreboard players set @a language 1

and one that says Spanish with the following:

/scoreboard players set @a language 2

With this we would have the basis in which the player has already selected his language; now comes the difficult part.
Each time your map shows text from a command block, you will have to have two command blocks connected to the same redstone signal.
Each one of them will be in a different language.
How do we make it that we can see on ourselves the selected language?
For example, if the command were:

/tellraw @a "Hello"

We are going to change it to these two commands :

/tellraw @a[score_language=1] "Hello"

/tellraw @a[score_language_min=2] "Hola"

Thanks for reading
if you have any doubts, discuss it here below

Español:

Se me ocurrió una idea para romper esas barreras de idioma que hay en los mapas, tan simple como un comando "scoreboard".
Consiste en ponerle un numero a cada idioma, en este caso;
"1" = Español
"2" = Ingles
(En mis pruebas tenia problemas usando el numero 0)
Para formar esto solo tendríamos que poner el comando:

/scoreboard objectives add language dummy

Luego hacer un sistema en el que el jugador pueda cambiar el valor de "1" a "2" o viceversa correspondiendo a su idioma, como por ejemplo, un botón que diga Ingles y ejecute el comando:

/scoreboard players set @a language 1

y uno que diga Español con el siguiente:

/scoreboard players set @a language 2

Con esto ya tendríamos la base en el que el jugador ya selecciono su idioma, ahora viene la parte difícil.
Cada vez que tu mapa muestre texto desde un command block, tendras que tenes dos commands blocks conectados a la misma señal de redstone.
Cada uno de ellos estará en un idioma distinto.
¿Como hacemos que solo vean el del idioma que seleccionaron?
Por ejemplo, si el comando era:

/tellraw @a "Hola"

Puede ser cualquier comando que le muestre texto al jugador
Lo vamos a cambiar por estos dos comandos :

/tellraw @a[score_language=1] "Hello"

/tellraw @a[score_language_min=2] "Hola"

Gracias por leer.
Si tienen alguna duda no duden en comentarla aquí abajo.