UPDATE:

Hello, Thanks for reading this <3
In update 1.2 I have added some more commands.

The commands that I added are:

/ss - Lets you freeze a player!
/unss - Lets you unfreeze as player.

/gmc - a shortcut for /gamemode c
/gms - a shortcut for /gamemode s

/tpbow - a really bad version of a telelport bow don't ask LOL

These new commands also have permissions.
You either need to be OP (server operator) that is the vanilla minecraft op.
Or have the custom permission.
You could use luck perms or something like that.

The permissions are:

Fly - ServerNeeds.fly
SS/UNSS - ServerNeeds.freeze
GMC / GMS - ServerNeeds.gamemodes
tpBow - ServerNeeds.tpbow

If you are an operator you will be able to use the commands without the permissions.