What were some of the characteristics of the early church?

This can get complicated because many things changed throughout the early church as described in the book of Acts.  At first the early church was completely Jewish, and they were looking for the immediate return of Jesus, this is why they gave away everything to the church (Acts 2:29-47).  As time moved forward God revealed the Church Age through the Apostle Paul, and soon Gentiles were included in the church (Acts 15).  As the message of Christ was spread into Gentile cities the churches began to change.  All the early churches were house churches, led and hosted by prominent members (Romans 16:3-5; Colossians 4:15; Philemon 1:2).  Historical records state that they would have a reading of the scriptures, would sing songs, and fellowship with each other.  It was not until around 200 AD that formal churches were established and 325 AD when they became commonplace.