Two thing to mention. Firstly, when getting the character, you should also use player.CharacterAdded:Wait() as the character could be nil when the script first runs (however, it appears your script is located under the character, so you could just do script.Parent to get the character).
Secondly, instead of using FindFirstChild, use WaitForChild for your variables.
Try using this code for your script
local char = script.Parent
local humanoid = char:WaitForChild("Humanoid")
local cc1 = char:WaitForChild("UpperTorso")
local cc2 = char:WaitForChild("RightUpperLeg")
cc1.Size = Vector3.new(4.068, 5.122, 4.24)
cc2.Size = Vector3.new(2.438, 4.017, 2.316)