In order to retire, we must first be debt free. No house loan, car loan, personal loan.
Next, we must have enough savings or passive income to last us for many years.

First goal - pay our HDB loan
Second goal - pay our other loans
Third goal - save money
Fourth goal - invest

How much to save? How much to invest?

It depends on how much you need when you retire.

If we need $3k per month from age 55 to 65, we will need $360k. After 65, we will get our CPF Life until we pass away.