There is no box to check to say you are retired. If you are worried about what to enter for "occupation" in MY INFO you can say "Retired" there if you want to. If you do not have a W-2 from working then you can tell the software you do not have any W-2's.
What income do you have? Social Security? Pension? Distributions from retirement accounts like IRA or 401K?
Go to Federal> Wages & Income>>Retirement Plans and Social Security (SSA1099 and 1099RRB) to enter your SSA1099.
To enter your retirement income, Go to Federal> Wages and Income>Retirement Plans and Social Security>IRA 401 k) Pension Plan Withdrawals to enter your 1099R.