What kind of bike should i get?

I'm 6'3 and 186lbs. but 14 so i am going to grow more. I mainly just need a bike to ride around my city and surronding ones, but i want to ride on both the streets/sidewalks, and dirt/rocky terrain. We have a lot of potholes and hills in my city... I have been told i need a hybrid bike already by a few people. Is this true? Can you recomend a brand for me cause i have no idea where to start?