How do Christians remember Good Friday, particularly in church?
Answer
The Bible doesn't specify any special way to celebrate Good Friday. It doesn't even require any celebration on that day, and some Christians do nothing to celebrate that day more than any other. (Since I am one of those, I am not sure how those that do celebrate it do so other than prayer and praise.)
We are to be aware every day of the sacrifice Jesus made for us on the cross, because that is what gives us forgiveness of sins. We may find in Acts 20:7 a reference to early Christians participating in the Lord's Supper on the first day of the week, but that seems to have been every week and not just one week a year.
On the other hand, the Bible does not forbid celebrating the death of Jesus on any particular day or in any particular way. So how you celebrate, or don't celebrate, Good Friday is up to you.