Of 30 hands, 10 point left, 10 point right, and 10 don't point at all. I need to have __ of these 30 handsto be certain that I have at least 2

This is known as the "pigeonhole" principle

To  absolutely  guarantee that you have at least 2 left-pointing hands, you would need to select - at a maximum -  22  of the 30 hands......of course.....you might not have to select that many.....but selecting 22 will guaranee at least two.....