High Connections is a neighbourhood coffee place north of SWUFE and Metro. The light, art, and soundtrack combine to make the cosy space good for lingering, and small and large tables on the upper two floors mean you can come solo or with a few friends.
Their drinks and prices are all average. I haven't tried the food there, with so many very good local options in the area. Espresso:
They have English corners on Wednesday and Saturday nights so if you go then it's normal to have local people ask to share your table and talk.