Two games, one code. How to decide? Thread

I started creating applications for the phone, and I'm just starting to learn how to write code on my own, for this reason I take the code partly from the Internet. Now I have one theme of two applications and I looked at both codes and realized that they are more similar ... Who knows how to avoid this? What would be the code for each unique?
Looking for a solution on the Internet, I found such a service, it seems to help, but maybe someone worked with it, what can you say?