Hello, Ruby. Here are a few pointers toward your essay.
First, the quotation about standing in one's shoes and walking around in them has to do with Atticus' advice concerning prejudging people. So, I think one of the main themes you should discuss is that of prejudice and tolerance (see the eNotes link below). Since part of your assignment is to discuss Scout's development over the course of the novel, you may also want to consider the theme of loss of innocence. The scene where Scout is standing on the Radley porch after escorting Boo back home completes the cycle of her learning experience with Boo--from the belief that he is a squirrel-eating monster to her realization that he is kind and heroic. She no longer needs to stand in his own shoes to see this--her view from his porch is now a different one (literally and figuratively) than she has experienced before.
You should probably consider the characters Scout, Jem, Dill, Boo and Atticus most prominently. Certainly, the trial of Tom Robinson--and the people she has met during the trial--have been a major source of her learning experience, so you may also want to include facets of this in your essay (as well as characters such as Tom, the Ewells and Dolphus Raymond).
I hope this helps a bit, and good luck.