Hello Rui.

Thank you for your purchase.

I am sorry to disappoint you, but Amelia doesn't let you add custom fields (like age) before selecting service, employee and date and time.

You can create separate services which would be named a certain age gap. Then, you can display the plugin in frontend via [ameliacatalog] to make it more eye-pleasing, although [ameliabooking] will also allow them to choose a different service (age). Then they would be able to see available time slots available for that service (age).

Yearly subscription (recurring appointments) is not yet a feature of Amelia, although we have it planned. You can make events to be recurring weekly, monthly or yearly, but that is an entire different setup, and wouldn't allow your customers to choose time slots.

Best regards.