Hi,
A lot of places to shop!
Platinum Mall (popular shopping centre for Singaporeans).
MBK (quite atas shopping mall)
Siam Square and Siam Paragon
Chaktuchak Weekend Market
Union Mall (dirt cheap brand goods)
Terminal 21 (a lot of food)
If you want to go night markets, i can recommend you Asiatique, JJ Green, Ratchada, Train night market and so on.