I need help constructing the concept for "Lovely's Lounge" -- 2

I plan to open an intimate lounge/bar/grill, which I hope to make locally famous for the fabulous live performances. I need help bringing the architectural design out of my mind and into the real world. I've come across some photos of different bars around the world that have elements I want to include in my establishment. I've attached those photos to this inquiry. I've never embarked on a project like this before, so I'm not sure if 3D rendering comes first, or a blueprint, or what. But I've got to start somewhere.