@Meeta: well, all templates have their differences. Fact

@Meeta: well, all templates have their differences. Fact is, that the Blogger widgets provide for all the wrappers I mentioned. But it is the choice of the template designer for which id's or classes (these are the html/css technical terms) he or she adds styling to stylesheet (the skin of your blog). So apparently, yours has no content-wrapper. What to do? The purpose of this tutorial is to make you understand how the stuff works, so that yuo can overcome such difficulties as you have encountered now.
So first, add the new sidebar section to your template, but don't bother with the styling. Then add one or two page elements to this new sidebar. View your blog, and in will be there, but probably not on the right place.
Now add the styling, which will probably be the same as the styling of your other sidebar.
If you have no content-wrapper, set the widths of your sidebars and your main so that sidebar+sidebar+ main = header-wrapper (or less). And see if it fits now.