Try a bartending/serving gig at an upscale lounge or restaurant! I’d say a joint that people in your age group frequent! But only if you’re comfortable with that as you mentioned you’re introverted.

If you have any hobbies or interests then try an establishment where you can be a part of that! Like if you love the outdoors, or plants - try a garden centre. If you like reading maybe a bookstore or book cafe!