How do I delete all the worlds and keep the main one

[EvilWU3]

It came to an issue where now everytime i join the world i spawn into new defaulth world. Because of that i had to put my old world on the server and delete all the other worlds. But i still spawn in the defaulth survival world when i join my server and I have to do the command to join my world. I tried the plugins Essentials & Essentials Spawn which didn't do much exept make me use /spawn to go back to my world, but the plugins also kinda messed up the basic commands such as /tp so i had to uninstall it.I checked the worlds and the files, but i can't seem to find ANY other worlds beside the one i uploaded. But somehow I am still getting teleported to that new survival world. I tried the "level name" thing on the control panel but it seems that this is causing the issue since it just created a new world instead of actully using the other even tho I spelled the name correctly ... Is there any way to fix this to set my world to the world that everyone would get teleported to when they join and delete the other survival world ?

[Endgator]

To delete a world, use the command /del world {worldname}.

I recommend getting the plugins Multiverse and MultiversePortals to teleport players between worlds (however, you can always teleport to a different world by typing /world {worldname}). Using this plugin, you can quickly teleport to a different world with /mv tp {worldname} and can set up teleportation portals with MultiversePortals.

If that doesn't work (or not what you were looking for) try the /worlds command and click the main world you would like to go on!

Hope this helps.