Likely, very focused on clear teaching of God's Word, and careful handling of the sacraments, within a reformed theology framework for faith and practice.
The size of the congregation, as in any denomination, makes a big difference in determining the character of the particular church.
Many congregations will have Sunday School or Family Bible School in times adjacent to the service, make a point to attend one of those as well to get a better perspective to answer your question.
Very likely, you will be struck by the high quality of biblical exposition, and the way covenant theology brings together people of every age, soli deo gloria.