Solution: Some third-party macro apps offer a setting called "Expanded by Default." The native Confluence Expand macro usually defaults to collapsed. If you need this specific behavior, you will likely need a Marketplace app.
Another powerful application is the page. Instead of a long list of questions and answers separated by blank lines, each question becomes an accordion header. The user reads the question and clicks only if they need the answer. This pattern has become so ubiquitous that users now intuitively understand how to interact with it. confluence accordion macro