Introductory or not, college classes are for adults, and if an adult can't deal with someone sitting in "their" seat, maybe they need to grow up a little bit. If the other student doesn't like that you're in their seat, too bad for them. You're paying for your education, and if a different seat will make the learning experience better for you, take advantage of it.
There were times in my college career when I would arrive to class and find someone sitting in my normal seat? You know what I did? I sat somewhere else.