How to smoothen this hole in a dry wall?

Hello all. I have had a very deep hole in my dry wall (I guess doesn't matter as it is very thin). I tried to cover it with the paste I bought from Amazon. No matter how much paste I put I can't get to smoothen this.

Are there any specific steps should I have taken? How can make sure they are smooth enough so that I can paint to make it look seamless as it was before?