There isn't really a visual editor for WP themes (although some Themes you can get have Options pages that makes it more like that).
*If* you really want to change parts of the templates, you do have to learn to read the code in the text-files. It actually isn't hard to start learning if you just read the text file, while looking at your webpage display, to see what's going where. A lot of the code has almost-English in it that you can read.
For example you're looking for the Google adsense in the code, well, it is the section of code that has the word "adsense" or "google" with a bunch of blah-blah-blah around it.
Before you make any changes, keep a back-up of whatever you're editing. Now you can find the block of code about "google" and delete it, save it (FTP), and re-load your page after this 1 change. If it worked, you're good. If not, try again, or ask a specific question here.
HOWEVER... If you are totally uncomfortable looking at the code, you can easily use simple good-old WordPress, because of these features:
(1) Themes. Just go choose a theme that is what you want, no modifications. There are 100's
(2) Widgets. Tons of themes work with Widgets which gives you the way to arrange your sidebar with any content you want, and remove anything you don't want, anytime.
Good luck getting started! It's not too hard to get what you want if you're patient and figure things out!