ATO is shorthand for Atahualpa Theme Options
you need to learn a little about CSS and what each of the options you want to use do. Here is a sample of code you can put in the ATO-> Page/Page Styling -> Post Container to play with:
border: solid 2px #000000;
margin: 0 0 30px 0;
If you want to know what each one does, do a google search with the term you want to know about and 'CSS'