We are using several accordians on different pages and the feedback we have received from public is that they do not understand that the accordian is expandable, even if you auto-open the first row. The icon is also static if you use and arrow that is pointing horisontal, you could like to have a toogle arrow that could swap horistontal / vertical dependant the according state close/open.
To guide the user the only way is to add text above the according informing that it is expandable.
When Joomshaper designed the Accordian, what design ideás was on the table and how to improve the user experiance to improve the guidance.
One page where the accordian is used:
https://www.excedo.se/en/email-security/mailscreen