A character analysis should focus on Atticus’s relationships with others, and what this says about him.
The most important relationship Atticus has is with his children. As a single father, he struggles balancing his work and home responsibilities, but he is always there for his children. You can tell by the way he talks to them, and the way Scout talks about him.
Jem and I found our father satisfactory: he played with us, read to us, and treated us with courteous detachment. (ch 1)
Atticus is not a hands-on father, but he does try to make sure his children know they are loved, and grow up to be good people.
Another example of an important relationship in Atticus’s life is his relationship with the town. He is well-respected, not because he is a Finch but because of how he behaves. This is why Judge Taylor chooses him to defend Tom Robinson, and why Heck Tate gives him the gun to shoot Tim Johnson. He is trusted.