Have you tried following the C++ language tutorial?
I'm a 'noob', like yourself. That you are trying this at your age says something about your will to learn, at least. It is a good idea to follow the tutorial, step by step, and code little things every time you see something new.
"So the chapter I just read is about variables.. Let's see how I can use those!"
Only when you fully understand a chapter, continue to the next one. Take it easy, give yourself time to think, and read the examples in the tutorial.
If you have any questions, then follow the format as stated on this forum to ask good and coherent questions.
(All the above makes up for a total of 666 characters. I knew that I was demonic, somehow!)
If, at any moment, you think "hey, this works!", then don't rest there. Only continue when you can say; "This works because of.. [INSERT REASON HERE]."
Programming is not 'writing some lines, some magic happens, and then the program works'. Never pause until you know the magic, and never blindly copy anything until you understand it.
You can cannibalize my code for the part which generates the coordinate grid, if you wish, and use that. But don't blindly copy. Try to understand it.