my wordpress site is using twentyeleven theme and i want to know more about

editing the html of it.

so when i go to editor, i see all these Templates that are php files. if i wanted to edit the html and put something, lets say adsense, on every page of this site, how would i do that?

or basically, how can i add a sidebar to this theme and make sure it always shows up on every page of this site, no matter the template used.

im thinking i would need to create a php file from a base sidebar design, and then from there edit the code of the main index file to allow this new sidebar template to always show up. correct?

i have no php or html experience, but i can post up whatever you want to see

1. You have to determine where exactly you want the adsense unit before we can tell you what to edit.

2. Widgets

I want it to the right of all my posts in its own sidebar. im using twentyeleven theme and it has an option for one sidebar, but im using that for site related shit. I want another sidebar on the right, on every page, and im just gonna put any size banners on it

but there’s no option for 2 sidebars in the theme appearance. how do I customize the code to install my own second sidebar?

how do i "use a child theme" ?

i created a child theme and made a new sidebar.php, but how do i edit that second sidebar that im supposed to have?
i dont see an option for it in Theme Options?