You can have morning or an afternoon slot or both, for the same trip on same day.
Booking Forms:
Create custom fields for custom booking forms and get any information you need. Like Weight or Height, Health issues (if any), etc.
Extras:
Often such Trips come with add ons like Photography or Guest Pick-ups. Add them as Extras and rate them separately. Making it easy for customers to select and they automatically reflect in the total amount.