I need help with scripting something

so i play a game called Ace Of Spadez and the "spread" in the game is isnt randomized AT ALL and you can predict where the spread will shoot.

i need a script that makes a line directly from the center and;

   when you look (lets say north (-Z axis) cause i dont actually know what direction is what in the game) the line would look towards the bottom.

   when you look east, the line would look to the right.

   when you look west, the line would look to the left!

   but when you look south, the line would look down not up.


thats all i really need, but if anyone can also help with this:
iof a block is like 40 studs away, the line would extend half an inch (about 1.25 centimeters)
and for every 40 studs it will extend another half an inch.

and if i may, please do 2 different lines, a red line for the first part, and a blue line for the second one, the blue being thicker and on top please
or just make the red slightly transparent.

thank you if anyone does this, im trying to learn lua, but right now i cant even code a CFrame in roblox studio without needing to google 4 different videos