How would I go around scripting it so I can see my torso, arms, and legs whilst in first person?

You don't deserve this for writing such a low-effort question, without even giving what you've tried or what you know. But I am bored and so, here:

game:GetService("RunService").RenderStepped:Connect(function()
    repeat wait() until game:GetService("Players").LocalPlayer.Character
    for _,v in pairs(game:GetService("Players").LocalPlayer.Character:GetDescendants()) do
        if v:IsA("BasePart") then
            v.LocalTransparencyModifier = 0
        end
    end
end)

Put it in a LocalScript in StarterPlayerScripts in StarterPlayer.