How you conduct yourself at funeral services depends largely on your degree of closeness with the one who passed or with the family left behind. As soon as you learn about the death, you can immediately pay the family a visit at their home, especially if you are close to them. If you are only a good friend of one of the family members, you can call them to extend your sympathy or wait until an obituary is posted for you to know if it is fine for you to go to the funeral. Some families may wish to keep the funeral private and would not expect you to visit. If you wish to attend, opt to wear black or any dark clothing to respect the family in their time of grief. Wait for ushers to guide you to your chair or choose a seat with considerable distance from the front and center. This will allow closer acquaintances enough room for themselves.
Be sensitive to the wishes of the family. If funeral flowers are allowed, you can address the floral arrangement to them with a short but sincere message. If you are in another state and would not be able to make it to the funeral, you can send a letter peppered with poems and quotes to express your sympathy and thoughts.