Hey Tannu, Places to be visited in Auli,Uttrakhand are : 1)Gurso Bugyal trek -short 3KM trek 2)Chattra Kund Lake 3)Nanda Devi National Park 4)Trishul Peak 5)Do skiing at Auli
Hi Tannu, here is a list of places you can visit while you are in Auli
Auli Artificial Lake
Gurson Bugyal
Chattrakund
Chenab Lake(You will have to trek to reach this place)
You can also do the Kuari Pass Trek if you love trekking
There are not many hostels in Auli except for on Youth Hostel Association of India hostel.