i would like to make a particle effect for all players in creative mode

Solution 1:

This is the syntax for /particle:

/particle <name> <pos> <delta> <speed> <count> [force|normal] [viewers]

In your case you didn't specify the viewers, so it defaults to @a. To make the particles only visible to players in creative mode you can use this command:

/execute at @a run particle minecraft:enchant ~ ~ ~ 1 1 1 1 10 force @a[gamemode=creative]

If you want the particles to be visible to everyone, but only be around players in creative mode, then you can use this command:

/execute at @a[gamemode=creative] run particle minecraft:enchant ~ ~ ~ 1 1 1 1 10 force