Pickup items and documents can be created from the Toolbox

By default, pickups have no visuals, you can simply add a StaticMesh component to the BP instance or, if it’s a repeating item (e.g. ammo, healing items, etc..), create your custom BP for each pickup using BP_HEItemPickup as a base class (Check BP_HEGreebHerbPickup for example)

You can then specify on the blueprint which item this pickup will give the player.