Enfold 3.3.2 / WordPress 6.0

Hi there,
i do the it- and security administration for a customer running WordPress 4.9.20 (!) with Enfold Version: 3.3.2. they left the whole page without any administration or any updates for at least 4 years, and now i have the task to close the detected vulnerabilites and do the upgrade of the whole environment.
now, due to the urgency of updateing the wordpress instance i have some questions:

1. i overtake the administration and i didn’t get any informations about the Enfold product (such as Themeforest User Name, Themeforest API Key which will be needed for the update of the theme and so on) and i have to know, wheter the version of my customer is a payed one or a free one and if i’ll do the update of WordPress to version 6, wheter i can upgrade the Enfold too or not.
2.will the version my customer owns be compatible with wordpress 6?
3. if i do the upgrade to WordPress 6, will it work also for the istalled theme Enfold 3.3.2 or do i have to update of the theme before?
4. do you know anything about my customer (registration, billing) ? i guess if there was a registration, the person who did it could be ” (Email address hidden if logged out) “, but unfortunately it was back in 2015 (guess) and the person don’t work for my customer anymore…

thanks for your help and your guidance in advance and kind regards,
beat tschanz