Здравейте, I am a Romanian living in France who likes to travel in the Balkans and try to know as much as possible about each Balkan country. I have the possibility to travel to Sofia and spend there some days for holidays in January. I have done the experience various times with Belgrade and it was awesome. I just want to explore the city, enjoying evening/nightlife (if existent), possibly meeting people and most of everything observing how people live, how they have fun, what are their lifestyles and values and walking a lot.
My question: is Sofia a city I can explore this way? I am watching to a youtube vlog right now and it's like there are some nice pedestrian zones. Other people told me Sofia is sad and gray. I don't know what to think. I am not looking for mass tourism, just conviviality.
I speak about 400 bulgarian words, this might help a little.
Please don't warn me about cold weather, I am not a snowflake, I lived minus 30° in my childhood, I just want a nice experience.
So... should I stay or should I go? :) Благодаря ви приятели.

PS - I'd also been for a short time in Ruse and Plovdiv and enjoyed a lot.