Use a collision volume, like sphere or capsule collision, configure it for overlap, on overlap destroy the actor and spawn an actor of the same class as the destroyed actor was at whatever location you want, then possess the spawned actor.
As Cestarian Pointed out, Inside your BP for the items that damage the player. add a collision component. After you set it up the way you want. Right click it and select Event>OnComponentOverlap. From other actor cast to your player character to ensure this event only fires when your character overlaps with the collision. Then from AS BP_Player( or whatever your player is called) get the node “destroy Actor”. I would also disable input as well but remember to enable it on your player’s begin play
For respawning: Something will need to trigger it whether that is a UI button or some other event. Then you just need to put a SPAWN Actor of Class node in what ever method you’re using to spawn the player.
If you want it to happen after a specific amount of time; Add a Delay on the end of the last image and then spawn actor of class.
I assume you have pre-determined points in which the player spawns? if so you will need to get the transform of that spawn point and plug it in here.