If you want a Gourami, just get one male - the more colorful ones are usually the males, though at times when young they might not be colored up all the way. The dorsal fin is usually more oval if female and more pointy if male. Sometimes these are opted to be the focal point / centerpiece fish if they are the bright blue or orangish ones.
A group of schooling fish would be nice if you see some type you like. Generally not too large of type fish like the size of Neon Tetras.
It seems you would have a large variety of fish available there.
These
https://www.liveaquaria.com/product/6587/?pcatid=6587
Microdevario Kubotai Neon Green (sometimes called yellow) Rasbora
Swims more at the top of the tank.
https://www.liveaquaria.com/product/6596/?pcatid=6596
Just start looking at the pics there at live aquaria and each one lists its tank needs so you can get the pics of the ones you might like and show them to the shop keeper of Tetras and Danios, etc. And do not really need to know Cantonese (as well).
Those types are schooling fish and want a group of friends to hang around with.
Do you know the water parameters you have?
pH
Alkalinity / KH Calcium
General Hardness (GH)
TDS