I just got a minecraft server

I got a minecraft server off of hosthorde.com. I immediately got on the server I bought and was on survival. I don't really want to be on survival and want to change my gamemode and be able to tp and do other commands. I type in commands and it says "I'm sorry, but you do not have permission to do this command" I don't know how to take control of my server and have already tried asking hosthorde and they don't give any good info. I have tried doing /op (my player name) which the same thing pops up, I don't have permission. I don't really know too much stuff, like how to get to the server's counsel or any of that! Let's just say… Explain it to me assuming I know NOTHING!