I agree ^. I am a super shy person once you initially meet me, and I can like stumble over my own words and mumble when talking to people. However, I have been an ED scribe over the past 2 years, and the one thing that doctors/PAs/NPs have all taught me is that you NEED to be confident in what you say. How else are you gonna talk to your coworkers? And in a healthcare setting, you are bound to disagree with someone, and you cant just go along with them and need to voice your opinion.
My college has a career services building, where they have mock interviews for grad school, and they tape you so you can see how you appear. They also have counselors that can practice with you, and Ive been seeing one for the pas tyear, who has given me a cheat sheet of what questions grad schools will ask you and how to answer it. Research your area, a local college should offer something like that