Howdy there!
You want to begin by doing op {your Minecraft username} in the server console (https://www.youtube.com/watch?v=repIG83dq2I might also help you in this). Also, ensure that you have the Essentials plugin installed (in order to install it, go into the Plugin tab on your Minehut server console -- https://minehut.com/panel/minecraft/plugins -- and search for "Essentials". When you've found it, select it and press the Install Plugin button). When you have OP-ed yourself, and Essentials is installed, start up your server and join it. Once in-game do /gmc or /gamemode creative (both will work). Now you should be in gamemode creative! NOTE: Other users won't have creative unless you OP them and they execute the command; remember that OP gives users access to all the server commands.
Next up, you want to go to your desired spawn point and do /setspawn which will do as it says on the tin -- set your world spawn.
If you need anything else in regards to your server, feel free to DM me on Discord. My name and tag are Clarifity#5587