how to break out of a loop when a condition is met/repeat until a condition is met?

Hey!

I'm fairly new to scripting and I'm having trouble how to figure out how to loop some code until a condition is met or repeat some code until a condition is met.

(any help would be greatly appreciated)

Here is my current script:

local value = game.Workspace.Value

if value.Value > 20 then

while true do
        wait(0.01)
    script.Parent.Material = Enum.Material.Neon
wait(0.7)
    script.Parent.Material = Enum.Material.SmoothPlastic
wait(0.7)

end
if 
value.Value > 20
then 
    break

end