This is some hard code I made for a Free For All tournament for a tournament on billymicmac.com (A SMP Server). You can use this to your liking.
A spigot 1.16 server, Essentials, and WorldGuard
Get the source code in IntelliJ and change the location object in the StartEvent and ResetEvent class to whatever you'd like as the spawnpoint. Then, ingame, put the items you want players to start with in your inventory and do /createkit FFA 0. If you are using a kit system other than essentials, you need to change the code in the StartEvent class to work with that
/startevent - Teleports the players to the start location and gives items, pvp will turn on 30 seconds later
/resetevent - Resets the event
This plugin is not plug and play - this is mostly help for anyone who wants to do something similar to this. If you want more help, contact me on Discord at AliveSteve#8899. If this gets 10 stars ill make it automatic and configurable.