Force yourself to smile and say something f like “good to meet you” or “thanks for seeing me” . Soft skills come naturally to some, but the tricks can be learned by anyone and are based on manners.
Have a couple of anecdotes about your approach to problem solving. Doesn’t matter what they are, there is no right or wrong answer, just have your approach ready in your head.
If its help desk, say you like helping people. One line i used a long time ago, was something like “I am quite shy on the telephone, but i actually helping people with technical problems “. It’s just keeping it real, a credible .
Consider de-emphasising your technical ambitions. They’ll have a dozen people saying they want to be a CCIE or data scientists or whatever the current flavour is.
Instead, I’d with “I’m doing well on with compsci degree, I don’t have any difficulties with the technical aspects, but I really want to see how my skills fit into a company, and make a start on understanding the realities of a business environment “
They want some one they can worth with, they can worth with almost anyone , but they won’t want to work with an “unknown”, so the more you can give - no matter who you are - the better.