I am applying for student federal aid and I have to link my tax information from my 2018 return to my application. I was in the military at the time and cannot remember if I used my PO Box or my home

[JotikaT2]

You can either log into TurboTax if you used the software in the past and log in to obtain the returns. 

Accessing prior year returns in TurboTax 

The other option is to order copies or transcripts from the IRS. 

Requesting copies of prior returns from the IRS