When I started out I did internships undergrad and post-grad. Some of them paid. Some of them didn’t. This was in the late 90’s.
I took two things away from that experience.
1. It sucks being an intern but it sucks even more if the corporate culture is shit. I’m remember myself and others being treated by a couple of assholes like a 24/7 personal assistant who would justify it as “this is how everyone starts off. ” when it was just them being assholes.
2. You got to live with what you signed up for. If you don’t like it quit and find something else to do because you’re probably not going to make it with that company. Just the way it is. I did that twice and one of the best decisions I ever made because both those companies went belly up when the dot.com bubble burst