how do I change the size and position of the TextLabel with script?

If you want to change the size and position of it then do this:

local TextLabel = script.Parent

TextLabel:TweenSizeAndPosition(UDim2.new(SizeX, 0, SizeY,0), UDim2.new(PositionX, 0, PositionY, 0),"Out","Style",Time)

Customise the SizeX and SizeY to the Size you want it to be. Customise the PositionX and PositionY to the Position you want it to be. I would recommend leaving the offset values to 0.

Customise the Style and the Time to the animation style you want and how long you want the animation to take (in seconds).

Here is a page you can look at for the animation styles:

Easing Styles

Here is an example if you don't quite understand:

--Example:

local TextLabel = script.Parent

TextLabel:TweenSizeAndPosition(UDim2.new(0.5, 0, 0.2,0), UDim2.new(0.1, 0, 0.6, 0), "Out", "Bounce", 1.1)