How do you group multiple children into having their values changed?

Hiya! So yesterday I think it was I asked a question about client-sided buttons which got solved easily.

My problem now is that there are multiple buttons to press and multiple button platforms to activate, as well as a reverse function.

In order to facilitate this I edited a script I received earlier (which worked fine until I added new buttons) to:

local platform = workspace.Button.ButtonPlatform:GetChildren()

game.ReplicatedStorage.PropertyChangeGood.OnClientEvent:Connect(function()
    platform.Transparency = 0
    platform.CanCollde = 0
    game.Players.LocalPlayer.PlayerScripts.SuccessSound:Play()


end)

Now nothing comes up at all in the log and nothing happens in game. I feel like I am a bit of an idiot atm because I know this script isn't right remotely but I'm somewhat stumped.

Things I have tried:

adding workplace. to platform adding worksplace.button.platform to it

yeah idk what to do, its prolly just a matter of adding 'local' somewhere but im stumped.

Thanks!