How do I make client-sided object?

put all your client sided objects inside a folder, then follow these steps:

workspace.ClientSidedObjects.Parent = game:GetService("ReplicatedStorage")

and then, inside a local script:

game:GetService("ReplicatedStorage").ChildAdded:Connect(function(child)
if child.Name == "ClientSidedObjects" then
child.Parent = game.Workspace
end
end)

So it will be local, i guess.