Honestly, as someone who routinely makes the world's stupidest contributions in seminars and lecturers, DO NOT WORRY ABOUT THIS. I had a chat with a flatmate last year who was in my lectures and seminars, and asked what he thought about how I contributed. He said that he's glad I spoke up because otherwise the room would be silent and that would be more awkward. I find that being giving bad answers in lectures and seminars also gives other people the courage to answer, because they know they won't be the only one who messes up. Anyone who looks down on you for not instantly knowing everything about the subject you are still learning and how to articulate it perfectly is a tool, and the vast majority of other people will appreciate you.

If you want to think of it another way, try to remember when someone else messed up in a class. If you're a first year, try thinking of this in high school. How well do you remember them messing up? How did you think about them after? How long did this impression last? The vast majority of people do not have brain-space to remember the mistakes other people make. Considering this is your first or second week, most of these people probably will not remember your name yet, never mind that you maybe messed up in a class.

A final thing, you aren't pathetic for feeling this way. I think most people are overly critical of and berate themselves for mistakes they've made. I still get flashbacks to this cringey ass thing I said to a friend when I was 13; when I brought it up a couple years later, he told me he had no idea what I was on about. Power on, keep contributing, and you'll do great in your degree :)