NEED HELP!!!

I dont think this is where you needed to post this. This should be moved to forums in help section. That being said i will still attempt to answer your question.

1.) Are you trying to make the whole server creative or just yourself? If you are trying to make it a creative server you need to enable creative in your server.properties file. This option is line 19 if using notepad++ (recommended and free).

If you are trying to make yourself creative and disallow for other players then ensure that you are an OP on your server. To do this go into your server console and enter /op frnc. Being an OP will allow you to enter commands in game without having to switch to your console. Assuming this is your issue, that should fix the error that you are getting in regards to entering the command.

Also in the future please explain in detail the error message and what you were doing when you got it. You will receive a more thorough answer and speed up the time needed to reach a resolution to your problem.

Hi it sounds like you arent op so go into the console screen do op frnc
then you can do /gamemode drnc 1 ingame