Make a selection with the /wand
Then follow these steps
1) /expandvert
2) //region claim (name here with out parenthesis)
Im not sure about if there is one or two slashes before it so try both.

1. Press t and type the command //wand
2. Left click one corner using the wand
3. Right click the diagnoally opposite corner using the wand.
4. Same as number 1 but instead of //wand use //expand vertical
5. Then do //region define name
You can change the name to whatever you want that area to be so you could use spawn for example.
Then you do //region addowner regionname(e.g. spawn as I mentioned earlier) player
player being which ever player you want to have build rights in that area. You can add multiple players to a plot you just have to do the command multiple times and the only thing you have to change is the players name.
6.(Optional)//region flag regionname greeting Welcome to place (place being whatever the area is called)
7.(Optional)//region flag regionname farewell Leaving regionname.



With 6 and 7 you can change anything after greeting/farewell.

I hope I helped!

can you come to are server
ip 2.223.243.208