The earliest you can start collecting Social Security retirement benefits is age 62; the latest is age 70. When you start collecting payouts in that eight-year span is up to you. Keep in mind, however, that the age you collect will affect the amount you receive in benefits; the longer you wait to start getting payments, the bigger the payments will be.
For the purposes of qualifying for benefits, your actual retirement date doesn't matter (continuing to work, however, may affect how much you collect. You can retire before 62 if you like, and you can retire after 70. If you retire before 62, though, you'll have to make sure you have enough money set aside to support you until Social Security payments kick in.