You need to pay for both parking and the entry fee. It's a small area that gets very crowded when the weather is nice. The canteen is quite small, so you might have to wait for a seat and table. There are better and more affordable places around Lake Attersee, but the view is pleasant.
While on a road trip, we spontaneously stopped at Attersee due to its stunning views. The beach was fantastic, with clean restrooms and showers. The water slide at the lake was enjoyable, and the water was incredibly clear. I highly recommend this spot. đź‘Ś