Willowbrook is a long ways from Evanston. Evanston is just north of the city; Willowbrook is a good ways southwest. If you're looking for Irish sessions specifically, there are many in the city, and one in downtown Evanston on Sunday afternoons at Tommy Nevin's pub.
The Old Town School listing is still current. That's about 30-40 minutes from Evanston by car, and accessible by public transportation as well.
As far as the Folk Dance Council of Chicago, I think you're best off contacting individual dance organizers, depending on your interests. What kind of dancing are you hoping to do? Hope this helps.
meg