Sandbox Help?

Hi, I’m probably the worst candidate ever to be using Sandbox, but I decided to give it a shot, reasoning that is was the only way to ever find a theme that was to my liking.

My problem now is this:
I know everything I want to do is doable with CSS. It would be VERY easy to simply ask someone to make the changes for me, but I’m stubborn and would rather learn where to put what in case I ever decide to be this foolish again. I’ve read extensively about how to do what I want to do, it’s the actual implementation that trips me up.

I know what I want, I know the general code to get what I want, but I have no idea what to do with it and how to customize it so that it’s exactly what I want (or as close as it can be).

I would also like to make some wordpress-related changes I have failed miserably at in the past.

If anyone could help I would be eternally grateful. You can either respond here or send an e-mail off to alessandra(DOT)palmer(AT)gmail(DOT)com.

Thanks!