Difference between PlayerJoinEvent and PlayerLoginEvent?

What are the differences between these two events?
When a player joins my server, I need to change his gamemode and teleport him, but whenever I add the code here, the person gets kicked for internal service error once, then they can join.
Please help.

Here is the error I get when I try to teleport/gm when they join.

Code:

21.05 16:58:09 [Server] INFO java.lang.IllegalStateException: Failed to add player. net.minecraft.server.EntityPlayer@e970(airnoah at -1577.0,61.0,-611.0) already is in chunk -99, -39
21.05 16:58:09 [Server] WARNING Failed to handle packet: java.lang.IllegalStateException: Failed to add player. net.minecraft.server.EntityPlayer@e970(airnoah at -1577.0,61.0,-611.0) already is in chunk -99, -39
21.05 16:58:09 [Server] INFO Disconnecting xxx [xx.xx.xx.xx]: Internal server error

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

PlayerLoginEvent

This event is used when the player first presses the connect button to login to the server. You usually check here if a player is banned etc.

PlayerJoinEvent

This event is called when a player has successfully logged onto the server.
This is the event you use if you want to have a motd. Or just a welcome message.