You know that lady gaga's big eyes partly thanks to makeup,so if you want your eyes bigger than hers, you need to learn how to make up.
First of all,you need a picture of lady gaga,then analyze it, just see what kind of stuffs do you need to draw your own big eyes.
Secondly, you should buy those stuff, then ask the shop assistant for help. The can guide you how to use them correctly. Actually, if you scarcely have idea of makeup, you can do the first step with the second step together.
Last but not least, draw your own eyes based on lady gaga's picture, but ,draw the eyeliner longer than hers and use the eyelash extension more to make your eyelash longer.