Boo Radley was a good person but perceived as someone who must be isolated. He himself chose to isolate himself from society. The justice about whether to judge him as a murderer or a defender was overlooked by Atticus because of Radley's history. The instability of Boo's family highlights the theme of how even within homes, equal human rights can be ignored. Aunt Alexandra is traditional and prejudice at first but becomes open to the views of Atticus because of her love for the family.
As an English speaker the advice i give to someone who wants to learn English would be it does take time but it's actually not that hard to learn English you just need to keep practicing and try to talk with the words you know so you can get used to it.