Wedding is a more formal and serious occasion. Dress appropriately and don't conflict with the groom. If it is in spring or autumn, you can wear a casual shirt with a linen suit and a pair of pants, which is very sporty and different from the clothes worn by the groom. You can choose to spend a little on your shirt, but not too conspicuous.
Just a little decoration will do. If it is in summer, you can wear a Polo shirt and then a pair of dark jeans. This will be more formal and decent, and you won't feel particularly lazy. Stylistically, it will be very comfortable and avoid hitting the groom.
Matters needing attention in attending the wedding:
Weddings start at auspicious times, and attending on time is a respect for the couple. This is not a dinner party, the wedding is a sacred ceremony, so be present in advance. At the beginning of the wedding, the participants should meet the speaker, and the host will control the venue and adjust the atmosphere according to his links. Out of respect, don't talk and eat at will.
Take care of your children. Avoid children crying and fighting at the wedding scene. You can't get married without a wedding. As friends, many people like joking. Once they joke too much, they will be embarrassed and may turn against each other.