How do I orient the face of an object to face the face of another object?

New at CFrame here!

I looked at the Roblox wiki for CFrame and more specifically 'Facing Toward a Point'

and I really do not get how this works at all :)

local GP = game.Workspace.Greenpart
local RB = game.Workspace.RedBlock

local RB_Position = RB.Position
offsetCframe = CFrame.new(0,0,-3)


GP.CFrame = RB.CFrame:ToWorldSpace(offsetCframe, RB_Position) -- Error 



print("Redpart Cframe =", RB.CFrame)

print("Greenpart Cframe = ", GP.CFrame)