Switching to Computer Science

So I’m currently in my first semester of my freshmen year and will be switching my major from biomedical sciences to computer science. I’ve always had an interest in computer science but never fulfilled it until now. How do I get more experience even though I don’t have any at all? How do I get into internships? Companies look for experience and I just want to know how I can get more experience even though I’m starting from basically nothing!