I don't think you can add bookmarks directly to the Safari toolbar. But, you can make the Bookmarks Bar visible using the keyboard shortcut Shift+Command+B. You can also see your bookmarks at the bottom of the Bookmarks menu in the Safari menu bar.
To actually answer the question, for the webpage that you want as a "shortcut" on the "toolbar"(Favourites Bar), do the following.
Click on the Bookmarks Menu in the Menubar. From the Dropdown, click on Add Bookmark. In the popup, click on the Options bar, then scroll and click on Favourites. Job done.