What I want to do is have an explosion trigger 5 seconds after someone sits in a seat. The only thing I need help with is what trigger or function to use. This is the explosion.
local explosionPart = script.Parent
local explosion = Instance.new("Explosion", game.Workspace)
explosion.Position = explosionPart.Position
explosionPart:Destroy()
The script is inside of the part I want to explode (a computer screen)

2 comments
seat.Occupant, not humanoid.Seated
Also, stop spoonfeeding code. Spoonfeeding does not help the asker know what their problem is and how they should solve it.