But yeah, call centers or large retail are probably fine if you're just getting your career started. There are tons of attractive young people who don't want to be there who you can get close to, drinks after work etc etc. It's almost expected at that level.
But if you're in a closer office environment, or if your reporting structure is "vertical", I would stay away from anyone in my own business unit or team. Larger work events, like trips or conventions are a safer bet as your meeting people from the company which can make for easy conversation, but you don't actually work with them. A lot of people come to those events to get drunk as hell and "release steam"...
A lot of professional folks, executives and the like, have met their spouses at work or work related functions tho. They live through their work and need to meet someone who understands that life. It's risky