When is a good time to Apply FE practicing Lua?

I have an above average knowledge about lua, but what I'm contemplating on is when a good time is to learn FilteringEnabled, or rather practice. I already know what what It does.

What I'm worried about is if I continue going the way I am without FE it could disrupt my flow sometime in the future.

tool = script.Parent
local char = script.Parent.Parent.Parent.Character

local en = true -- cooldown Animation
local sw = false
local on = 1


tool.Activated:connect(function()
    if en == false then return end
    en = false
    local char = tool.Parent
    local hum = char.Humanoid
    -- animation
    local anim = hum:LoadAnimation(script.Parent["Animation"..on])
    anim:Play(0.2,1,1)
    sw = true
    wait(0.5)
    sw = false
    on = on + 1
    if on >= 3 then
        on = 1
    end
    en = true
end)

local ten = true -- cooldown damage

tool.Handle.Touched:connect(function(hit)
    if sw == false then return end
    if ten == false then return end
    ten = false
    if hit and hit.Parent:findFirstChild("Humanoid")then
        hit.Parent.Humanoid:TakeDamage(15)
        wait(0.5)
        ten = true
    end
end)

Just a basic sword script ^

This is just an example of what I'm currently doing, and if I should simultaneously practice events etc, + FE combined.