Hanoi city day tour

Have just found out that you dont need a guide to discover Hanoi. Travelling by yourself is really awesome. But besides, i also found out that i need a Hanoian to be my companion. To have a Hanoi city day tour by yourself is not that much impossiblle if you guys are new here, but only sightseeing then it's okay or else you really need a guide. I want to taste Hanoi cuisine but not those in luxury restaurants. I'm interesting in street food. Small vendors always attracts me as i was in Hong Kong. So is there any suggestion for me about Hanoi group tours from any travel agent which is good to book. I would like to travel in a group without hesitation of strangers people.