Could Someone Help Fix This?

local player = game.Players.LocalPlayer.Humanoid

if player then
	player.Humanoid.Health = 10
end

I've tried to get this to work, but it just won't. Anyone have any advice?

The player does not have a humanoid; for this reason you must instead use the following: local player = game.Players.LocalPlayer.Character.Humanoid

local player = game.Players.LocalPlayer.Character:findFirstChild("Humanoid")
if player then
    player.Health = 10
else
end

Should I change it to:

	player.Humanoid.MaxHealth = 10
end

?

local player = game.Players.LocalPlayer.Character:findFirstChild("Humanoid")
if player then
    player.Health = 10
end

The one below will also work you just have to put it into a LocalScript and into StarterGui.

Put it in a LocalScript in StarterGui. LocalScripts can only go in players backpack or PlayerGui (PlayerGui = StarterGui) Scripts can't run LocalPlayer, only LocalScripts.

local player = game.Players.LocalPlayer.Humanoid

if player ~= nil then -- ~= means it's the opposite. So if it were to say = nil, that means if it is nil it will work, if it is ~= and Humanoid is nil, it won't work.
    player.Humanoid.Health = 10
end