How do i make this script take 5 seconds to be at max speed?

After reading and organizing the eye straining question on my end, I finally came up with a solution...

Here it is.

-- PUT THIS CODE IN A LOCALSCRIPT UNDER THE StarterCharacterScripts!

-- Game > StartPlayer > StarterCharacterScripts



repeat
    wait()
until game.Players.LocalPlayer

m = game.Players.LocalPlayer:GetMouse()

local TweenService = game:GetService("TweenService")

local maxSpeed = 32 -- Use this variable instead to change the speed.

local goal1 = {}
local goal2 = {}

local humanoid = script.Parent.Humanoid -- It's best to use variables.

goal1.WalkSpeed, goal2.WalkSpeed = 16,maxSpeed

local TweenInf = TweenInfo.new(5,Enum.EasingStyle.Linear,Enum.EasingDirection.InOut)

local slowDown,speedUp = TweenService:Create(humanoid,TweenInf,goal1),TweenService:Create(humanoid,TweenInf,goal2)

m.KeyDown:Connect(function(key)
    if key == "0" then --“Shift to run” 0 == shift
        print("Running")
        speedUp:Play()
    end
end)
m.KeyUp:Connect(function(key)
    if key == "0" then
        slowDown:Play()
    end
end)

By the way, ^ ^ ^ ^ THIS ^ ^ ^ ^ is a code block.