Making the most of this summer

Hey guys,
I am doing a sophomore summer internship at a shop with very light hours (9-5 basically) and everyone here is OOF by 6. I am from a rural town and wanted to make the most out of being in a big city that has variety of opportunities. I am hanging out with friends on the weekends but wanted to use the working days to network or grow professionally as I don't think partying on let's say Tuesday adds anything to my life. Do you have any ideas on what I could do in the afternoons/evening for an hour or two to leverage big city's opportunities and gain better business understanding and build my network? I was thinking about inviting other people for a coffee to chat or going to startup pitches but maybe you have other suggestions? Any advice would be helpful.

inb4 you call me a hardo, I'm literally asking what I could do for a few hours a week which may be very helpful in the future in either professional or private life so please don't use your time to hate