Like with most Pokémon games, Pokémon Scarlet & Violet have multiple gyms spread across the region. These gyms have no set path so you can seek them out however you want, whether you go for the strongest straight away or when you happen upon a town. In the region, you have to go through the Gym Challenge and defeat them to take on a special test known as Champion Assessment to obtain the Champion Rank
This page is to detail all the gyms, and the Gym Leaders and their Pokémon.
Gym ?: Glaseado
Gym Leader: Grusha
The Ice-type Gym in Paldea is run by the Gym Leader Grusha, who used to be a Professional Snowboarder. He uses Ice-type Pokémon such as Cetitan