The absolute most important question you must answer is "Where do you live now." More specifically, where is your permanent residence? Where are your doctors, dentist, children's school, voter registration, drivers license and car registration and so on. I don't see that you answered clearly, but you say that you are starting a new job, will "work from home" in VA, and relocate to NC later. You must be clear on this point, I feel you have missed the importance of the question.
If you are a permanent resident of NC now, you must report all your world-wide income to NC and pay NC income tax on it. Even if you are temporarily out of state. You will file an NC resident return.
Then if you are working temporarily in VA, you owe VA a non-resident income tax return that reports income earned while living or working in VA. NC will give you a credit for taxes you pay in VA that will offset most of the effects of double taxation. You would file either an NC-4 or NC-4EZ (they are equivalent) and a VA-4. VA-4B is not correct, that is for a Virginia resident who must pay out of state tax. You may want to make manual adjustments to your NC-4 to reduce your withholding so you get more money in each paycheck instead of a huge tax refund from NC at the end of the year, but that is beyond what we can advise on. You may want to speak with a tax professional.
However, if you are a permanent resident of VA for now, then you only owe VA income tax. NC does not tax you for income that you earned while living and working outside of NC, even if the company is based in NC. NC will only tax you if you relocate to NC either temporarily or permanently. For now, you only file a VA-4. If the company insists you file an NC-4, claim exempt.
