You can just ask random people for quests!

I went to a pub and asked this guy if he had any missions for me. He turned to me with a serious look, said and I quote: "I need you to recover an 8GB white Toshiba flash drive I lost around here yesterday. It has some valuable information, but it's encrypted, so dont go snooping in. If you find it for me. I'll make it worth your while."