We went to buy splendid red bream at the fish store.
This fish shop floor is very slippery, so be careful.
The fish shop gave me a 100 yen discount.
A fish shop is a fish shop, a place from which you buy fish. Especially in Japan, very important.
The kun'yomi reading is used for the 魚 (so it's さかな) and the kun'yomi reading is used for 屋 (や). You'll have to use the reading of 魚 from the vocabulary from a couple levels ago to remember the reading of this one.