Hey Manuela,
Glad to help you out on this thread as well ๐
To modify how tickets are displayed you’ll need to create a template override (check out out themer’s guide for more details on this) of the file: wp-content/plugins/event-tickets/src/views/tickets/rsvp.php. Once the copy of the file is placed in your theme (wp-content/themes/you-active-theme/tribe-events/tickets/rsvp.php), you can modify the html for the tickets form (description is printed at line 77).
Please let me know if you can make it work,
Best,
Nico