I volunteered at a library and was hoping to have a varied experience. Nope! Every time I spent the session tidying the shelves and returning books to the shelves, involving lots of bending and stretching. Fine for a while, but really boring for three hours at a time.
I also did the training to volunteer at the CAB, but I was really irritated by the insistence on a commitment to defined sessions each week, with the requirement to book holiday time and no flexibility in the days worked. Cheeky I call it, when it's costing money in fuel etc, to get there in the first place.
I've tried three times to volunteer at a food bank, but been told each time that there are no vacancies and that they'll be in touch when there are. Never happened.