Yes, you do. Up to 85% of your Social Security benefits can be taxable. There is no age limit for having to pay taxes on Social Security benefits if you have other sources of income along with the SS benefits. When you have other income such as earnings from continuing to work, investment income, pensions, etc. up to 85% of your SS can be taxable.
To enter the W-2G or other documents For your Gambling winnings--Go to Federal>Wages & Income>Less Common Income>Gambling Winnings
You can enter your winnings, and then keep clicking through the interview to enter gambling losses.
Gambling losses are an itemized deduction; you can only get a deduction if the combination of all of your other itemized deductions exceeds your standard deduction. Losses do not offset winnings dollar for dollar.