do i also enter my military tsp roth ira contributions as a deduction or just leave on w2 information section

Just leave it. The program picks up that information from the W-2.

 

Additionally, Roth contributions are made as after-tax contributions and there is no deduction on your tax return for contributing to a Roth IRA.

 

The advantage to a Roth IRA is that a qualifying distribution may be non-taxed. 

 

 

And to be clear, the federal TSP is not an IRA of any kind.