I make the assumption you are asking how to move the cursor around the iPad...
To precisely place the cursor, press and hold on the screen until you see a small magnifying glass pop up. While still pressing the screen, move your finger around - the magnifying glass will allow you to "zoom" in enough to see where the cursor is. This makes it possible to put the cursor in the middle of a word, or wherever you wish.
There are no arrow keys on the default/stock virtual keyboard. So, this is the method Apple has designed to aid in editing. After some practice, it actually works pretty well.
Hope this clarifies (and is what you were asking about).
Marilyn