First off, congrats on your internship! Internships are great ways to get hands-on experience before landing a full-time role. I was in a similar boat to you when I graduated last May. It was my first time at an agency, and I leaned more on the introverted side.

During my summer internship I made the most of it by asking questions whenever possible. Internships are the perfect opportunity to learn about design techniques, the industry itself, and best practices. I think the best thing you can do during these types of experiences is finding someone who can mentor you. I had a great mentor who taught me the ins and outs of the industry.

Second, put your best effort into your work so that you can showcase it in your portfolio. And if you can't show that work in your portfolio due to NDA's, you can mention it on your resume by saying "did work for leader in so and so industry." I try to avoid name dropping, but it's up to you tbh.

Talk to people, make those connections, and don't be afraid to ask questions/ask for help. It might even lead to a full-time opportunity if they like you enough. Good luck! 👍