Know the difference between omniscient point of view and multiple points of view. Omniscient goes into everyone’s head in any given scene. Multiple viewpoints concentrate on one character at a time, but covers several throughout the course of the story.
Multiple is usually more effective for reader engagement. Your POV character should be able to tell a lot about what others are thinking by their actions, body language, and facial expressions, just like you do every day. Remember that verbal communication is a very small percentage of what a person projects. Such cues are often more effective for conveying emotion than dialog alone.