Set their CFrame using an offset of the AdminPosition
Add or try to increase the offset. To make players spawn Around the admin, not in the same position.
Thats enough to fix that players collide with each other on teleportation, but could sometime fail and select a random position pretty close to a previous spawn.
If you want to go more advanced, create a table of used coordinates, and spawn players based on coordinates enough far from each other to totally get rid of “players spawning at the same spot”
First try to use the random offset I already suggested, if its not enough cause its a big party of players to be teleported, then go for to build the “advanced” mode