How do I make my beam face toward the mouse, and how do I make other parts copy the beam's cframe?

So what I have is a local script, remote event, and a server script. In the local script, I check the mouses's position, and in server script make the beam face toward that mouse.

Local Script:

local rp = game:GetService("ReplicatedStorage")
local event = rp:WaitForChild("RemoteEvent")
local player = game:GetService("Players").LocalPlayer
local Mouse = player:GetMouse()


	Mouse.Move:Connect(function()
		
		local MousePosition = Mouse.Hit.p
		
			event:FireServer(MousePosition)
			
	end)

Server Script:

local rp = game:GetService("ReplicatedStorage")
local event = rp.RemoteEvent

event.OnServerEvent:Connect(function(player,mp)
	local beam = player.Character:FindFirstChild("beam")
	
	beam.PrimaryPart = beam.Cylinder

		beam.Cylinder.CFrame = CFrame.new(beam.Cylinder.Position, mp)

end)

So, a few problems I have here is when i run the script, my beam attack's (a model with parts and a cylinder located inside the characters model) cylinder faces the mouse a little, but only tilts a little against my mouse position. It stands straight up. What I wanted to do is the cylinder to be horizontal and turn to my mouse, not tilt and straight up. Another Problem is that I set my cylinder to the primary part of the model, but the other parts does not follow the cylinders cframe(face the mouse a little). Can anyone help me solve these two problems, and make the cylinder out of my hand too? Also, sometimes the beam is laggy and doesn't follow the cursor.