Are you talking about clothing-wise? For me, it all depends on the weather, but always starts with layers. Out in CA, it doesn’t really get that cold in the mountains so I just wear pants with some stretch for the bottom, an undershirt, hoodie, and jersey for layers up top, wool socks on my feet, and if it’s really cold a beanie on my head. When I was growing up in the Midwest, I’d wear thermals top/bottom and maybe a second layer of socks, plus a scarf or gaiter for my neck/mouth. I’d also throw some hand warmers in my pockets for when my hands got cold. At some point my feet would inevitably get cold so I’d take my skates off and use the hand warmers on my feet, but in general I heat up quickly so it’s better to be able to take layers off rather than overheat and soak your clothes.
If you’re talking gear-wise… skates/gloves/stick (obv), and if I’m playing a game, shins and possibly a helmet. A lot of the surfaces I play on are deeper lakes which are black so I have orange and white pucks which are easier to see vs a standard black puck. I also never go on a lake without a hand drill and ice picks. Gotta be safe and too many people die every year because they didn’t take necessary safety precautions before enjoying the ice.