You can take a bus from Pathein or Yangon. The roads are not that good, so for the about 260 km from Yangon it will take about 6 hours, depending what bus you take. You can also go by boat from Yangon to Pathein.
You may rent a bicycle or take the bicycle taxis.
The endless and quiet white sand beach, the lover's island, there is an 'elephant camp' in between Ngwe Saung and Pathein.
Go to the beach, see the local village. There is not much to do in Ngwe Saung, that's the idea. Just relax and enjoy the quiet time.
Painted umbrellas made in town or in Pathein.
There is no disco, however the very modern and stylish Bay of Bengal hotel has sometimes disco like events.