masism

I'm trying to change some things around on the top horizontal menu bar but can't seem to find anywhere to do that. Any help would be greatly appreciated. I'm new to all this so I'm missing some of the fundamentals, I'm having a hard time just figuring out where to look to edit the code at ex. editorial.tpl, header.tpl, global.css, etc. Once I figure out where it should go I can go move along. Another question I have is when I look at the source of a webpage (right click view source) can this html be edited and where can I find it in my bo to edit? Thank you

having some problems so i took down the link

Hello, I'm trying to make the left and right margins of the webpage thinner. I'm using the matrice theme and I've put a new background on but can't seem to adjust the size of the margins. thank you