Hi! Firstly, thank you!!
Yes, you do have to buy tickets but they’re not super expensive (I think its about $15 for grandstand tickets on a normal day. Grand Prix day is a bit more expensive and sells out pretty quickly). You can also just get general admission tickets (there is seating next to the ring, but it is in the sun and can get quite hot). Those tickets are less and are great if you don’t want to pay for a grandstand seat.
Once you have your ticket (usually they sell tickets for the day performances - everything from 8am to about 5pm - and then evening performances from 7pm and later), you are free to roam around and watch as you please. You can go back to watch schooling or wander down Vendor Row, or visit the Carnival. :) Its a pretty relaxed atmosphere.
Yes, you can take pictures without being an official show photographer, you just cannot advertise your photography services (like handing out business cards or approaching people and trying to get them to buy your photographs). But if you’re like me and just want to watch and take photos for your own enjoyment, that is 100% allowed. :)
Purchased tickets for Devon a few days ago. I’ll be there for the Hunter Derby (and possibly a few of the jumper classes if I get there early enough) and the Grand Prix later in the day. Then I’ll also be there on Saturday for the A/O stuff (going to watch both the A/O stuff in the Dixon Oval if I get there in time and the locals in the Gold Ring. Also hoping to hang out by the schooling area for a little while.