Using Pen Tool draw a star shape like you remember from your childhood. Once is done, using the star shape, create two new shapes like in following image:

Make a new layer and paste the last two shapes done. Hide the first layer with the star basic shape. Fill the shapes with blue and orange color grandients.

Now, arrange the shapes to form a star like the basic star shape is. For the next step you need to make 3 new shapes (with Pen Tool) for a small 3D star effect. Those shapes will have a more dark orange color or gradient. Each star corner will meet the center of shape. Left one will have a full orange color, middle one a 90° angle grandient, right one at 45° gradient.

This is how you image look now:

Place a shadow shape like in following image and make the happy face star. Copy now all shapes and combine them, fill the new shape with a light grey and place it behind the character. Use Free Distort effect to create a perspective character shadow.

Done. Bravo. You are a star!