List five things scout finds strange about the church and service at First Purchase Church.

First Purchase is Calpurnia's church. She takes Scout and Jem with her one Sunday because Atticus is out of town. This takes place in Chapter 12, and all the quotations used in this answer come from that chapter.
Scout is confused by how much of a fuss Calpurnia makes over how they dress for church. Calpurnia makes Scout wear a heavily starched dress with a sash, and she spends a lot of time going over Jem's clothes, even though she usually trusts him to make his own decisions in that regard. 
Scout also doesn't understand why Calpurnia changes the way she talks while she is at church. When Calpurnia is at the Finch house, she uses Standard American English (SAE). However, at the church, she uses African American Vernacular English (AAVE).
The interior of the church is not what Scout is used to. Not only was it unpainted, but "[t]here was no sign of piano, organ, hymn-books, church programs—the familiar ecclesiastical impedimenta we saw every Sunday." Scout is particularly perplexed by the absence of the hymn books.
She does not understand why Zeebo says the lines of the hymn first, only to be followed by the rest of the congregation (a practice called lining). Calpurnia later explains to her that most members of First Purchase cannot read. 
Scout also observes that "Reverend Sykes then called on the Lord to bless the sick and the suffering, a procedure no different from our church practice, except Reverend Sykes directed the Deity’s attention to several specific cases." She notes that Reverend Sykes is also more likely to name specific individuals who, in his opinion, need to behave better.
Scout is particularly shocked by the way Reverend Sykes raises money for Tom Robinson's family. Sykes is comfortable asking his congregation for even more money when he deems the first collection unsatisfactory. Once again, he even chastises individuals who have not given and calls them out by name.