If I joined the military after I quit my civilian job do I still check the boxes for that W-2 ?

What boxes?  Did you get a W2 from both jobs?  

@ginger9505 

If you joined the military in 2021, and you received a W-2 from the service (DFAS) for 2021 , then yes, you check the box that it was a military W-2 on the page after the main W-2 form with all the various checkboxes. 

 For the civilian W-2, you don't make that selection....each  W-2 stands on it's own, but both are entered into the software.

_____________________________

And...if you did join the military in 2021, then you indicate that also on the My Info page where you enter information about yourself.

________________

But if you joined more recently, in 2022, then you do neither of those until next year's tax filing in early 2023.