We also have what you might think of as a "traditional" service on a Sunday where there is a reading from the writings of L. Ron Hubbard that is usually something applicable to the lives of those attending. There can be other things at the service, such as group auditing (auditing delivered to more than one person at a time also called "Group Processing") and live music. Other than the reading there are no set rules.
Sunday Service is not as big a deal in Scientology as in other western religions, but that is because we go to our church much more often than just on Sunday. As you read in my earlier articles on Scientology Training and Scientology Auditing, these are the "big two" and a person might be on course five evenings a week, so they might not attend the Sunday Service. But if you are not on course or getting auditing, then Sunday Service can be a nice thing to attend for the sense of community it gives.
There are also Scientology ceremonies that mark major points in life such as naming ceremonies (what you'd call christenings), marriages and memorials (funerals). Also other events are celebrated such as minister ordination.
One can also go to the Chaplain for help on personal matters or if one has a dispute with another Scientologist, marriage problems, etc.