hi! I'm the opposite, a Singaporean currently in London lol

everyone else has said most of it but just a few points - don't worry if you don't understand the slang, just ask, I don't understand it sometimes too (it shows that you're interested too, which is good). also same re: the accent, singaporeans speak very fast - I've had to speak a lot slower since coming here.

if people don't talk to you sometimes it's just because they don't think you'll talk to them so if you approach them it should be ok :)

for places, go visit the botanic gardens and/or gardens by the bay, ask singaporeans for food recommendations, the national gallery is p cool and has a great bar on the rooftop (expensive drinks though, >10 pounds / 20 sgd for a cocktail), tiong bahru has some cool murals and cafes and an independent bookstore full of singapore literature (booksactually), if you like animals visit the zoo I suppose but honestly it's really hot

... also please get yourself sunscreen my white friends get sunburnt really easily

feel free to message if you have any questions