Your Public Booking page URL is found in Calendar - Share. See screenshots below.
Online bookings will only be possible if you have availability set up and your Booking Preferences are set to allow it.
You can use this URL anywhere - your email footer, in online ads, mention it on voicemails, or link through it it from text or a button on your website or a Book Now button on your Facebook page.
Read about adding additional directions to your business, when GPS isn't enough.