So I'm trying to make the character move 15 studs in the direction the head is looking at. Instead it just moves one certain direction.
plr.Character.HumanoidRootPart.CFrame = plr.Character.HumanoidRootPart.CFrame * CFrame.new(plr.Character.Head.CFrame.lookVector * 15)
try this:
plr.Character.HumanoidRootPart.CFrame = CFrame.new(plr.Character.HumanoidRootPart.Position + plr.Character.HumanoidRootPart.CFrame.LookVector * 15)