Join Leave Signs

1. [impulse] /scoreboard objectives add joinSign trigger

2. [impulse] /scoreboard objectives add leaveSign trigger

3. [impulse] /scoreboard objectives add playerCount dummy

4. [impulse] /setblock ~ ~1 ~ minecraft:oak_sign{front_text:{messages:["",{"text":"Leave Game","color":"#FF9BFF","click_event":{"action":"run_command","command":"/trigger leaveSign add 1"}},"",""]}}

5. [repeat] /scoreboard players enable @a[tag=!joinedSign] joinSign

6. [chain] /execute as @a at @s if score @s joinSign matches 1.. run tag @s add joinedSign

7. [chain] /execute as @a at @s if score @s joinSign matches 1.. run tp @s ~ ~10 ~ 0 0

8. [chain] /execute as @a at @s if score @s joinSign matches 1.. run scoreboard players add testGame playerCount 1

9. [chain] /execute as @a at @s if score @s joinSign matches 1.. run scoreboard players reset @s joinSign

10. [repeat] /scoreboard players enable @a[tag=joinedSign] leaveSign

11. [chain] /execute as @a[tag=joinedSign] at @s if score @s leaveSign matches 1.. run tp @s ~ ~20 ~ 0 0

12. [chain] /execute as @a[tag=joinedSign] at @s if score @s leaveSign matches 1.. run scoreboard players remove testGame playerCount 1

13. [chain] /execute as @a at @s if score @s leaveSign matches 1.. run tag @s remove joinedSign

14. [chain] /execute as @a at @s if score @s leaveSign matches 1.. run scoreboard players reset @s leaveSign

15. [impulse] /execute as @a[tag=joinedSign] at @s run tp @s ~ ~5 ~ 0 0

16. [chain] /execute as @a[tag=joinedSign] at @s run tag @s remove joinedSign

17. [chain] /scoreboard players reset testGame playerCount

18. [repeat] /execute unless score testGame playerCount matches 0..10 run scoreboard players set testGame playerCount 0

19. [chain] /setblock ~ ~1 ~ minecraft:oak_sign{front_text:{messages:[{"text":"Join Game","color":"#FF9BFF","click_event":{"action":"run_command","command":"/trigger joinSign add 1"}},[{"score":{"name":"testGame","objective":"playerCount"}}, "/10"],"",""]}}