How can I trigger functions in a script without waiting for it to finish before firing another one?

local function action(Pick, part, OldFrame, OldSize)
    if Pick == 1 then
        for i = 1, 4 do
            part.Parent:SetPrimaryPartCFrame(part.CFrame + part.CFrame.UpVector * 2)
            wait(0.1)
            part.Parent:SetPrimaryPartCFrame(part.CFrame - part.CFrame.UpVector * 2)
            wait(0.1)
        end
        for i = 1, 20 do
            part.Parent:SetPrimaryPartCFrame(part.CFrame - part.CFrame.UpVector * 5)
            wait(0.05)
        end
        wait(3)
        part.Parent:SetPrimaryPartCFrame(OldFrame)
    end
end

while wait(1) do
    local index = math.random(1, #script.Parent.Grounds:GetChildren())
    for    i, v in script.Parent.Grounds:GetChildren() do
        if i == index then
            action(math.random(1, 2), v.Block, v.Block.CFrame, v.Block.Size)
            print('done')
        end
    end
end

This is supposed to make different tiles in a little grid go down. How can I make it so it doesn't have to stop until one if finished in order to start another

You can try using while true do is a good way to repeat make sure you add wait(.2) Example

while true do
wait()
blank --put your code you want to repeat
----
---
wait(.2)

Is this what your wanting?? Hope this helps!!

Alr. So what I wanted from this script is to trigger a function and work like a remote event. Just to start it but not wait for it to finish. and you can do that by just placing the function in a spawn()

For example:

local function gg(function(plr)
	spawn(function(plr)
		for i = 1, 50 do
		plr.leaderstats.Cash.Value += 5
		wait(0.2)
		end
	)
end)

while wait(1)
	gg(Player Variable)
end

This is going to run the function every one second but function is 10 seconds long. So it can run it multiple times without waiting the 10 seconds.