I tried that, says I don't have permission. Contact your server administrator...lol
I found this on the wiki, but I can't seem to find an admin.txt or an ops.txt
Configure the server by editing the server.properties file, the format for which is explained here. Be certain to edit the file with a text editor that does not add formatting (e.g., for italics). Additional configuration may not be necessary as many servers run fine from the default values.
Add your username to the admin.txt and/or ops.txt (newer Minecraft versions may not have an admin.txt file).
Ops.txt and admin.txt determine who may execute server commands. In other words, operator ("op") privileges allow you to control certain aspects of the game (e.g., teleporting players).
Op privileges may also be granted from the server GUI: type "op <username>" and it will automatically add <username> to the ops.txt file. Being an op will not let you fly and/or have a creative inventory