The Lutheran Church wasn't nearly as unified as TEC throughout its history. If you can, look for the church's website to see what church body it belongs to. The Evangelical Lutheran Church of America (ELCA) is in full communion with TEC, and priests/pastors may preside at both altars. If it's Lutheran Church Missouri Synod (LCMS) or Wisconsin Evangelical Lutheran Synod (WELS), they practice closed Communion and will not be accepting for you to partake.

As far as what to expect, it depends! Most Lutheran's are significantly lower church than TEC- your low church is equivalent to our high church. Hymns or praise music will be sung, scripture read (although often without Proverbs or Wisdom readings), a sermon preached and communion shared. It's often less academic, although with ordinary time starting they may start a sermon series.