If you have a 401(k through your employer, your contribution is reported in Box 12 of your W-2
with the letter code D.
Because your contribution
is included in your W-2, do not re-enter it in the retirement section.
As your Roth IRA is not deductible, you are not required to enter it into TurboTax, but if you do, the program can track basis information for you which may help when you sell.