The door opened and an old woman walked into the izakaya restaurant by herself.
An alive alcohol shop is a place that does a lot of alcohol. In Japan, these places are often izakaya, or, if you don't know Izakaya already from English, you can consider it to be a Japanese Style Bar.
The readings here are all kun'yomi, but this is the first time you've seen the さか reading for 酒, which rendaku then turns into ざか in this word! If you know what an izakaya is already, it will help you to remember the reading, but if not here's a mnemonic to help you:
After soccer (さか) practice, you always go to your favorite izakaya!