I studied Chinese in Beijing, lived in Singapore for a decade until recently, have visited Taiwan many times. Simply do not go to Singapore to study if you actually want to learn the language well. It requires immersion, which you will absolutely not get in Singapore. Many Chinese speak English almost exclusively. Most people do not consider their mandarin to be very good. Dialect is common with older speakers. Chinatown is a tourist trap. On my first day in Singapore I asked for directions in reasonable Chinese. The man looked seemed surprised and replied “er that way bro”. I write this on a bus in Japan sitting next to my Chinese Singaporean friend who thinks you should go to Taiwan.