You have finally made it far enough in your career that someone has slid into your DMs asking for a meetup to "pick your brain." Congrats! This is an honor, even if you do wish to charge for your consulting services (hey, your time is valuable!). Personally, I try to help out non-vulturey young people wishing to break into the biz for free (then again, I rarely check my DMs). In any case, this particular sort of social interaction calls for a unique approach to venue-picking.