Our akad nikah is at a mosque. What etiquette should we observe, including clothing and photographers?

Remember that a mosque is a house of worship first, and a venue second. The bride and women guests should cover their aurat fully; avoid tight or sheer clothing. Women who are menstruating may not be in the prayer hall, so ask the mosque about a suitable space. Brief the photographer not to step over the prayer rows, not to go up onto the minbar and not to disturb worshippers who are praying. Loud music, cheering and clapping are not suitable inside a mosque. Plan the akad time so it does not clash with congregational prayer. Contact the mosque management early to learn their rules. See akad at home or at the mosque.