Idiom: Golden Opportunity, noun phrase.
Example #1: John really likes Anna. Unfortunately, they are in different levels. John is a very shy guy and it’s difficult for him to start a conversation with her. Last weekend, John’s classmate, Kim, had a party at his house. Kim knows both John and Anna, that’s why they were both invited to the party. John had a golden opportunity to introduce himself to Anna and let her know of his existence. He didn’t miss his chance and now they are a couple!
Meaning: Golden opportunity means a perfect chance to do something that will benefit you. The party where John could be in the same room as Anna was a great chance for him to become friends with her.
Example #2: Marry is a big boss at a very big and successful company. She has been working like a horse, day and night. There is so much work that Marry hasn’t had a vacation in the past 3 years! One winter there was flu virus that was spreading fast all around the company. More and more people were getting sick every day. The management of the company decided to let all their workers stay home on a paid vacation for 3 days to recover and avoid getting sick. It was a golden opportunity for Marry to forget about her work and just relax.
Meaning : The three days off that Marry got unexpectedly was a great time for her to just relax. She took advantage of this great chance. There word “golden” doesn’t mean that’s something is made of gold. It means something is very valuable.