To create a complete world for your hero or heroine, these places and people must be a part of their world. You need to show your characters in their environment, in their element. It is through these interactions that readers will get the greatest glimpses of who your characters are at their core.
Your Homework: Pick a place or two that matter to your protagonist. Try to envision it in your mind. This is what you want to convey to your readers. Use your senses to describe what it looks like, what it sounds like, what is smells like.