If no commands work, it may because WorldEdit failed to start: Make sure that you are running Bukkit/Forge/Sponge/etc. A vanilla minecraft server will not load plugins/mods! You can run a command such as version (Bukkit), sponge version (Sponge) or forge help (Forge) to ensure your server is running proper software.

How do I get WorldEdit to work?

Drag-and-drop WorldEdit's . jar file you've downloaded into the mods folder. And you're good! Simply launch the Forge profile the next time you start Minecraft, and WorldEdit will be there and working.

Do you need op for WorldEdit?

If you are using Bukkit, then you need to have permissions to use WorldEdit. You can give yourself op ( /op yourname ) to give yourself permissions. ... If you are using Forge/Fabric server, then only ops can use WorldEdit.