Welcome Cal! Have fun with the software and on the forum!
The best way to get started using NESMaker is by following the official tutorials on the New 8-Bit Heroes website: https://www.thenew8bitheroes.com/learn
Make sure you start with the module tutorials (especially the intermediate and advanced ones) to get a global idea of NESMaker's possibilities, and the Twelve Days of NESmas to learn more about the different software components.