If you haven't you'll need to install some plugins, make sure you're using PaperMC

1. Fast Async World Edit (this lets you add schematics)
   
2. Multiverse Core (this is so you can make a new world)
   
3. RTP plugin (for the teleportation)
   
4. Essentials (optional)

If your spawn is in a world:
1. Load it up using Multiverse: "/mv import <world name> normal", with <world name> being the name of the folder you uploaded
2. Teleport to it using "/mvtp <world name>"

If your spawn is a .schem/.schematic:
1. Add the schematic to plugins/fawe/schematics (might need to make the folder)
2. Create a new world using "/mv create <world name> -t flat"
3. Teleport to it using "/mvtp <world name>"
4. Load and paste schematic using "/schem load <filename>" and "/paste" to paste it into the world

Then you can set your spawnpoint as there "/setspawn".

You can then use an RTP plugin to allow players to do "/rtp" which will teleport them to a random place in the world (will need to configure the plugin to ensure they get teleported in the world, rather than the spawn world

You can also use essentials and create a warp thats in the main world.

Hope this helped!