This task can be pursued in a couple of ways. The first would be to develop a thesis statement about how friendship is shown in both works. This is going to be dependent on your own analysis and your own understanding of the material. Basically, it comes down to how you see friendship in both works. Ask yourself how George and Lennie operate as friends. Are they "good" friends to one another? Do they support one another? Where do we see instances where they are good friends and where are there moments where they are not good friends to one another? Is there sacrifice between them, a necessary component of friendship? Then, ask these same questions of Amir and Hassan. After this, I think being able to contrast how the friendships of both sets of characters are different from one another will help you immensely. Essentially, I think you will find that both are good friends to one another, although the concept of friendship is a bit different. I don't think you will get far without speaking to the idea the George and Lennie stick together until the end when George has to shoot Lennie and that Amir and Hassan experience a distancing in their friendship, only to be salvaged when Amir returns to "be good again." I think that experiencing the friendships in these questions and contexts will help out a great deal in composing this paper.