Zoom is a general setting that can be used on all web pages. As such it is in the Opera menu in the upper left. You can also use keyboard shortcuts to adjust it. It is a per website setting so zooming one page wont zoom them all. You can use it on Opera internal pages also, like speed dial and bookmarks.
Anyway, posting 3 times in the same thread over the course of 15 minutes is considered poor form. Please don't do it again.