Usage patterns
〈事〉の儀式を行うto hold/perform a ceremony (for something)
They held a wedding ceremony at the shrine.
儀式に参加するto take part in a ceremony
Many people took part in the graduation ceremony.
儀式を執り行うto solemnly conduct a ceremony (formal, often religious)
The monk solemnly conducted the funeral rite.
〈人〉が儀式を司るfor someone to officiate a ceremony
The village elder officiated the ceremony.