Experience helps. I’ve taken the Myers-Briggs test a few times, and every single time I’ve been 100% introverted. I’ve now been with my volunteer agency for one year, and i’m much more comfortable with my colleagues. Having finished my EMT last year helped also, as I’m more confident with what I’m doing. Ask questions about your vehicle, the equipment (what is ___ used for?, What does this button do?). You’ll both be learning, and interacting with your coworkers. And that should lead to be your being more open with them. Talk with patients in the back of the ambulance during transport. I found that very hard to do, but as I forced myself to talk with patients (what do you do? Where do you work? Where did you serve in the military? Tell me about your family. Are you hot or cold/comfortable? How can I help?) I became more comfortable and came out of my shell. You just have to do it, but you can start slowly. Good luck!