Please help me understand these questions.

[sorb2021]

Did you make contributions to a retirement plan when you did not live in Virginia?

Does this just mean for the tax year?

I contributed to a 401k whilst in Texas, how do I know if this was taxed by Texas?

Enter the long-term capital gains that qualify for a Virginia income subtraction.

Where do I find this information?

[ColeenD3]

Are you a part year resident of each state? 

Enter the long-term capital gains that qualify for a Virginia income subtraction. Where do I find this information?   

If you moved out of state, you are only going to include the transactions that occurred during the time period you lived in VA as income. You will have to look at the dates of the transactions.