Is there tube sliding hills for kids here? What else kind of activity are there for kids?

There is a Tubing Hill in Summit Park which is across from Jeremy Ranch area west of Park City open only during winter months when there is snow good luck have fun

In the summer there are many hiking/biking trails and at the botton there is a large slide and little roller coaster for the kids. No tube sliding in winter, that's at Soldier Hollow. There are easy beginner ski trails though.