Hello
I'm Making a game like Terraria it's a 2d 8bit pixel sandbox game that I'm making I have no experience in coding and I don't no witch I should use and how to code I am creating all the terrain it is not being randomly generated because there is a story line I'm on a Mac so how do I make a game?

Well, if you want to learn how to program, Python is a great language to learn. You'll have to learn how to program before you can make a game like Terraria, though, and it might take you a few years.

If you just want to play around and get something up and running quickly, GameMaker is pretty fun. The Lite (free) version is good enough for starting out.

If you want to make anything, through any method, the most important thing is to keep trying, NOT by switching what you use every few weeks, but by sticking with whatever tool you use, even though it may be difficult, and to keep trying to learn for several years. So, don't give up, regardless of whether you choose either of the two above or some other method.

I would try out SDL. It should work on a Mac OS X. See here: http://wiki.libsdl.org/moin.cgi/FAQMacOSX

It's a good framework for 2D games that can be extended with other libraries to 3D if you so desire. You can get more information here: http://www.libsdl.org/

Also, it is much easier to understand what you are trying to ask when you put each thought in its own sentence and drop a newline in-between them.