You can qualify for retirement  benefits when you turn age 62, but not until the first full month of being 62.  So unless your birthday is the 1st or 2nd day of the month, you won't be eligible until the next month after your birthday.  (The reason the 2nd day works too is that for SS purposes you reach your age the day before your birthday.)

The amount of the benefit depends on your average earnings over the highest 35 years.  The benefits range from an average low benefit around $800 per month, to almost $2,400.  The amounts can be higher if you delay getting benefits until after Full Retirement Age.

You must have at least 40 Quarters of Coverage in employment covered by SS, meaning you paid SS tax, also called FICA, on your earnings.  This amounts to a total of 10 years, but it doesn't have to be continuous.  It can be spread out over your worklife.

If you take benefits at age 62, the amount will be reduced for early retirement, up to 25%.  The reduction is based on how many months before Full Retirement Age (currently age 66) you get the first benefit. 

If you are under 66, then your earnings may affect your benefits if you are not completely retired.  See the earnings limits on the Home Page.  If you earn less than the annual amount your benefits will not be affected.  If you earn less than the monthly amount, then your benefits will not be affected no matter how high the annual earnings, but you can only take advantage of this monthly provision in one year.