Trends and development in your industry would be perfect topic to showcase your understanding of and vision for the trade you are in. Read some review articles; know the catch phrases to use or a few controversial issues to watch, and prepare some original ideas or opinions or predictions to discuss with your boss. Ask him what impact do all these trends have on the company’s future?
Discuss career development plans with boss and seek his advice/suggestion. Ask him: What is the appropriate way to advance on the career ladder in your case? What the lesson he learned as a junior like you? What is the secret of success in his case? Let him talk about himself and you just show your admiration and make a few comments. The bottom line is that you need to show you care about your job and your career.
He might not spend any free time with you during the meeting. He might spend all the free time with you. Choose the subject wisely and casually. It’s no big deal.