I'm pretty sure you need to get some experience in coding stuff. All ideas come to my mind to track items/prices in nexus requires coding. So if I were you I'd start learning how to code or such. But tbh it's gonna take a while so don't rush things. If you are interested in 2D games and creating your own game I can recommend you Gamemaker studio. It's how I started coding then moved to C# + Unity. There are so many resources online waiting for you. But if you want to see what's happening inside RotMG just download JPEXS decompiler, get rotmg's current swf and open it with JPEXS. Have fun