Want a non-stop stream of advice? Mention to your (marathoner) husband and (marathoner) brother that you need a training plan for your first marathon. Then sit back and listen to the contradictions roll in:
Run slow to go fast.
You need to up your pace if you’re going to finish in that time.
Your easy runs should be REALLY easy.
If I were coaching you, I would definitely push you more on your long runs.