GG12, the important thin at the moment is to get to the stage where you can comfortably run about 10 miles once per week, and train 4 days per week minimum, before you start a "proper" plan in about december. So start by going out for 3 short runs per week build the distances up, and gradully lengthen the weekend long run, until , by the end of the year, you are hopefully ready to start a trainig plan.
You could start with something like a half marathon "get-you round" plan, and when you're finished with it, then switch over to a marathon plan. I did a get you round marahon plan, followed by an intermediate one, for my first, but did the increases in LSR distances more gradually, spread over the whole time period.
The advantage you have is that you have much more time to build up than the tradtional 16- 18 week plan, so your risk of injury will be less, as you can take it much more slowly.