From airport you can take a bus ticket for 24h or 48 h or 72h , we took one of 72h for 7€ , you can use it for all buses and getting to upper Bergamo too. Bergamo is a nice city to visit.
The appartement is on 3d floor without lift, that's important to know, it's written though in the site. Beds are confortable. The hosts are very kind. You can use the kitchen for breakfast.very good equiped everywhere, the only little negative thing for us is the low water pressure in the shower.
Around there is a lot for food. From the airport you can take bus N*1 to the central station in the city ,then Bus N*8 to the appartement .