There are many places suitable for you to stay in Nanjing. Express hotels only cost 100-200 yuan per night. You can stay near Hunan Road. Just search for hotels near Hunan Road in Nanjing on Ctrip.
It will be very convenient for you to go out if you live on Hunan Road. I will give you a simple route arrangement. You can take bus No. 1 from Xuanwumen bus station to Sun Yat-sen Mausoleum. It is now open for free; there are also You can visit the Underwater World, Plum Blossom Mountain, Ming Xiaoling Mausoleum and other scenic spots together. There is a small train that can go directly to the Sun Yat-sen Mausoleum;
After visiting the Sun Yat-sen Mausoleum, you can take Tour 2 to the Presidential Palace Station Get off the car and go see the Presidential Palace; the ticket price seems to be 80, I went there last year;
After the end, you can continue the tour at the entrance of the Presidential Palace 2, and go to Confucius Temple to taste Nanjing’s snacks and delicacies. Visit the scenery along the Qinhuai River and buy many small souvenirs there.
From Confucius Temple, go to Sanshan Street Station and take Metro Line 1 to return to Xuanwu Gate.
The next day you should take bus 33 from Xuanwumen Station and get off at Yuhuatai South Gate Station to visit Yuhuatai Martyrs Cemetery for free. After that, take Bus 4 at Yuhuatai South Gate and get off at Mochou Lake Station. Take the bus to see Mochou Lake Park. After getting out, take bus 4 or 7 and get off at Chanan Jiangdongmen Memorial Hall Station to enter the Nanjing Massacre Memorial Hall for free. After coming out, take Metro Line 2 to Yunjin Road Metro Station and get off at Xinjiekou Station to visit the most prosperous business district in Nanjing. After that, take Metro Line 1 back to Xuanwumen.
If there is a third day, you don’t need to take the car and go directly to Xuanwu Lake Park to relax. If you are interested, you can go to Jiming Temple to worship Buddha.
So it is most convenient to live near Hunan Road. I hope you have a pleasant trip to Nanjing!