It is common to have specific seating arrangements at funeral services. Generally the immediate family sits in the front rows, the extended family in the following rows, followed by close friends. There are some cultures or religious services that may have limited or no seating at the church or venue and it is appropriate to stand or sit on a particular side. This can vary considerably - please make yourself aware of the requirements by observing, or asking if you are unsure.
Traditionally people think of wearing all black to a funeral, and this can still be the case with some religions or cultures. However, in many instances it is not essential that black is worn. It is usually appropriate to wear conservative clothing and to be well groomed. There are circumstances where family may request that people attending the funeral wear something in particular to celebrate, or which is representative of the deceased, such as a particular colour or style. In these instances it is entirely appropriate to follow the wishes of the family if you wish to do so.
Turn your mobile phone off before walking into the funeral, and make every effort to ensure that you do not arrive late or leave early.