Codebase was a mess, inconsistent commenting, unneeded classes.
Massively disorganized when I was there. Had to often pick up tickets on my own while waiting for my manager to be free from his flood of meetings, so my tasks were all over the place.
Unlikely you will be creating anything new, mostly just code maintenance and optimization. You may be adding new features, possibly, it very much depends on the team you're on.
Pay for interns is laughable. I earned more than others at $11, the average was $9-$10.
They love reorganizing everyone desks occasionally for no discernible reason, I would like to have a desk and be there unless there is a legitimate reason to move me.