Important: this is not a contact request. I just want help!
Here is the homework:
A little information: It must be scripted. Unfortunately I'm not so good because I'm still a beginner.
So do your homework until tomorrow:
The / build command
command / build:
permission: lobby.build
trigger:
Here's the stuff
Help: Use the variable {lobby.build.active.% Uuid of player%}
Query whether the variable has the value true (If your variable is true) or (If your variable is not set).
And to activate build, you delete the variable or set it to true.
Then you have to find the place where the moving of items, etc. Is blocked in the script.
And then just block that (there's probably a cancel event or something) if your variable "is not set" AND query the permission again (If Player has permission "lobby.build").
I know it's not a really helpful answer, but if you don't know and it may take a little time for an answer to come up, just ask your dev if he'll explain it to you again. It's nothing bad, especially if you're still a beginner.
I don't script myself, so I can't help you with the code.
As such, I would say that script is not really something to learn. I would recommend you learn Java. You have more options and can do them if you need them later. With script you can do less later.