Remodel the interior to fit your design. Repaint and remodel the inside of your space to match your design that you thought up earlier. Work with the space you have, taking advantage of unique features and covering up flaws. Do as much of this work yourself as you possibly can to save on costs. And remember, when you're just starting out, the quality of the art is much more important than the quality of your gallery space. Focus on the art and the money for cosmetic improvements will come.