In order to begin to answer this question effectively consider the social issues at work in Great Expectations-- family relationships, social status, justice, criminality, working class vs. educated middle class, etc.
Then consider how individual characters are shaped both by the larger social setting and sociological pressures placed on them, and by their individual ambitions, passions and choices.
Some character comparisons that might be useful in exploring the conflicts and relationships between social problems and personal ambitions:
- Biddy and Estella-- Biddy is content, aware of her status, and has no desire to change it. Estella is discontent, also very aware of her status, but not very self aware. She seems powerless in comparison to Biddy.
- Magwitch and Mrs. Haversham-- both characters have been victims of society, and have chosen proteges through which to exact their revenge on the society that wronged them. How are they similiar? How are they shaped by society, and by their individual passions? How do they succeed/fail
- Pip, Herbert, Wemmick-- All of these characters are similar in age and intelligence. They all have separate ambitions. Pip is more driven by his place or lack of place in society than either Wemmick or Herbert. What are the consequences for him, how do the others rely more on their individual ambitions? How does socitey thwart them, help them, or serve them?
These are just a few comparisons that might help you to begin thinking about this question.