Door wont open when touched?

Make sure you put your code in a code block next time.

This is your script.

script.Parent.Touched:connect(function(hit)
    if hit.Parent:FindFirstChild('Humanoid') then
        local plr = hit.Parent:FindFirstChild('Humanoid')
        if plr.Parent.leaderstats.kills >= 1 then       -- This is your error.
            script.Parent.Transparency = 1
            script.Parent.CanCollide = false
            wait (0.5)
            script.Parent.CanCollide = true
            script.Parent.Transparency = 0
        else
            print("ha")
        end
    end
end)

Assuming leaderstats is a model and kills is a NumberValue, what you're basically outlining is this:

if plr.Parent.[Model].[NumberObject] >= 1 then

You're comparing literally an object to a number. What you might be intending to do to wipe away the error is comparing its value.

Therefore:

if plr.Parent.leaderstats.kills.Value >= 1 then

I detected a potential logic error in this script. A better way to make sure that it is the player it is detecting, not a random NPC (if you do have NPCs, or any model(s) with a Humanoid in it), you can use the :GetPlayerFromCharacter() method. If you do not have any models with a Humanoid in it, then by all means skip this.

The :GetPlayerFromCharacter() method literally gets the player from the character object.

The formula goes like this:

game.Players:GetPlayerFromCharacter(--[[ Insert valid character object here ]])

EXAMPLE

script.Parent.Touched:connect(function (hit)
    local Human = hit and hit.Parent and game.Players:GetPlayerFromCharacter(hit) and hit.Parent:FindFirstChild("Humanoid").Health > 0 and hit.Parent:FindFirstChild("Humanoid")
    if Human then
        print("Player detected. The Player's name is ".. game.Players:GetPlayerFromCharacter(hit.Parent).Name)
    end
end)

I added the Humanoid's health bit just in case if the body part themselves are touching it, but the character died.

Also, double check if the leaderstats model is where it's supposed to be. By convention (in my terms), it is located in the Player model.

game.Players.LocalPlayer.leaderstats