Draco is two too!
And I'm sure you're right about the socialization since I do live alone. His behavior is literally just shops/cafe patios and where he can't get to all the people he sees. I take him to friends places if there's a get together where new people are coming and going, and he's fine when people come over. He does well at parks and such though I guess because there are more interesting things than just people.
Perhaps more trips to the pet store and just starting there will be something to work, I only go like once a month but will try once a week like you at your job. It's the only place I can think that I can practice these tips I found.
So far this youtube video seems the most helpful to me. Many of the videos have the tips of ignore then reward when they are quiet. But doesn't work because he's quiet at home.
Teach Dog to Stop Barking - Treatpouch