Is there away to efficiently damage a player via server?

I'm trying to make a damaging system. So I need to figure out how to damage a specific player through the server because I've recently learned that damaging through the client is just stupid. So to test difference methods of damaging I'm trying to damage the player when they join the game. Here is one of my attempts below:

local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(player)
    local Humanoid = player.name
    Humanoid.Health = Humanoid.Health - 5
end)

I tried this because of the Humanoid.Health property. And I chose to use the players name as the humanoid because I read from an article that you can fetch the Humanoid by getting the players name.

So yeah, feel free to roast or lecture me below, it'll help out a lot.

You can get the humanoid from the character, not the player name. Calling :TakeDamage on a humanoid damages them unless they have a force field.

player.Character.Humanoid:TakeDamage(5)