Don't think its just a piece of paper. see the video below.
Step 1: Paper
The only thing you will need is a rectangular piece of paper which has 12.7cm length and 5.6cm breadth.The paper should be normal it should not be very thin or not very thick.
Step 2: Folding It Into a Book Shape
Fold the paper in half
Step 3: Folding It Into a Shape of Bird
Now after folding it into a book shape then open the book and fold as shown in picture
Step 4: Launch It
Hold it like a paper plane and throw it very slowly if does not work then hold it upside down and try it. Both launching methods are shown in the pictures and if you still don't understand watch the video below.