en_tn/act/09/28.md

He was with them, going in and out around Jerusalem

Here the word "He" refers to Saul, and the word "them" probably refers to the apostles and other disciples in Jerusalem. This is an idiom meaning that Paul was able to associate freely with the believers in Jerusalem. (See: rc://en/ta/man/jit/figs-idiom)

in the name of the Lord Jesus

Possible meanings are 1) this simply refers to the Lord Jesus and tells who Paul spoke about. Alternate translation: "about the Lord Jesus" or 2) "name" is a metonym for authority. Alternate translation: "under the authority of the Lord Jesus" or "with the authority that the Lord Jesus gave him" (See: rc://en/ta/man/jit/figs-metonymy)