When I travel alone, I usually use my camera, food and a Kindle as my main defense against feeling alone and bored. Here is a good example from one evening in Norwich last autumn, when I had spare time, but nothing I wanted to do in the evenings.
A trip to a chippy (fish and chips shop).
Very busy, very nice art, really good chips.
Then found a pub and had a couple of pints while I read Terry Pratchett.
Nice details. I take more pictures of these things now that I actually need to buy such things myself.
Had a cocktail because I felt like it.
Then tried out the waffle place I had passed a couple of times on my way home. Chose waffle with chocolate mousse and a pot of tea.
I think I finished the entire book that evening….