At 25 it is pretty straight forward. Buy a set dollar amount of ETFs monthly (aka dollar cost average). ETF just choose the Vanguard ones (VOO, VTI etc).
The other options are generally not as favorable:
Real estate in HK is too expensive for cashflow investment. To make real money you are betting that the market will go up. Unlike stocks it is also maintenance heavy and illqiuid.
Insurance based products offer downside protection, but are generally quite expensive in fees.
Fixed income, returns are just too low, makes more sense when you transition from accumulation to preservation at a later age.