1 Week in Sofia

I’ve seen a few posts when searching in this sub for Sofia but none are recently so I figured I’d ask again. Heading there for a week in the spring. I am open to any and all recommendations for things to do, places to eat, where to stay, etc. All I have booked is the flight! 25M, able bodied, no issue with 10-15k steps per day, English and Spanish fluency, well traveled throughout Europe and especially solo.

Interests include: wandering around exploring neighborhoods, bookstores, fun bars, great traditional food, I usually do check out the stereotypical tourist spots for at least a bit everywhere I go. History, architecture, football. Hiking to an extent.

Ideas: day trip to Plovdiv, possibly a bus to Skopje for a day and a half or two? Any good cities in Serbia near the border?

As specific or broad you would like to be, all are appreciated. For example one of my favorite recs I could receive are along the lines of “there’s a small coffee shop in this alleyway on random street. The pistachio croissant is amazing and the barista is this chill old man. Go hang out there and read for an hour” . Or from my last trip “go to Sighisoara. It’s amazing”

Thanks and hopefully people in the near future can find this post helpful as well.