take sightseeing bus line 1 and line 2 in Shanghai

Yes, you can do that, but you should remember to get off the bus line 1 at SH Urban Planning Exhibition Center (People's Square), so that you can take the bus line 2.

It takes around one hour and a half for Line 1 and it takes around 50 mintues for Line 2 .

The closest station to your hostel is the Nanjing Road (East) Station at Exit 2 of Subway Line 1, Henan Middle Road. You can try to walk to that place.