What is another script for it and can someone fix this error?

Use :IsA(). The shirt and pants are part of the Clothing class. :IsA() checks to see if something is a certain class. For instance.

game.Workspace:IsA("Workspace") --true
game.Workspace:IsA("Clothing") --false

if statements check to see if something is true unless you tell it to check if it's false or not true.

if game.Workspace:IsA("Workspace") then
    print("Workspace is a workspace.") --This will only print
end

if game.Workspace:IsA("Clothing") then
    print("Workspace is a shirt or pants.") --Because this is false
end

Now we mix it with your script so we get...

dist = 10

function onClicked()
    local players = game.Players:GetChildren()
    for i = 1, #players do
    if (players[i].Character.Torso.Position - script.Parent.Position).magnitude < dist then
    local name = players[i].Name
    local clothing = players[i]:GetChildren()
    for i = 1, #clothing do
if clothing[i]:IsA("Clothing") then
    local f = game.Workspace:FindFirstChild(name)
    local s = f:FindFirstChild("Shirt")
    local p = f:FindFirstChild("Pants")
    local s1 = script.Parent.Parent.Parent.Clothes.Shirt:clone()
    local p1 = script.Parent.Parent.Parent.Clothes.Pants:clone()
    s.Parent = script.Parent.Parent.PlayerStorage
    p.Parent = script.Parent.Parent.PlayerStorage
    wait()
    s1.Parent = f
    p1.Parent = f
    wait(5)
    s1:remove()
    p1:remove()
    s.Parent = f
    p.Parent = f
end
end
    end
    end
end

script.Parent.ClickDetector.MouseClick:connect(onClicked)