To put it in perspective... I can go 16 mile long runs in the 5:50s, but I can't go sub 4:30 in a mile.
So, try and get to at least 40-50 miles perk week. Buy good shows. Get new shoes every 300 miles. Log your miles on your shoes. Try to get your regular training pace below 7min. A GPS watch is amazing. Then, once you are at 40mpw, which could take a new runner a few months to get to (try and add a few miles per week), then throw in workouts like tempo runs, fartleks and intervals. You can google those and find out what they are. Want a book? https://toptalkedbooks.com/amzn/1450431836
Do you have any idea what your current race times are like? It would be a good idea to try to enter some small local 5K or 10K race in the not too distant future to judge your starting point, and give a realistic estimate of your fitness to determine what paces you should actually be running at for training.
It would also be a good idea to do a half marathon race before a first marathon. Jumping straight from little long distance running to a marathon is not something I would ever recommend, although with your fitness base from soccer, you would probably have a better time of it then most people who do this.
I would honestly recommend targeting Pittsburgh as a half marathon, and perhaps looking at going for a full marathon in the fall of 2017 if you decide you like long distance racing well enough to train properly for it. There is too much mystique around the marathon causing people to think they "have to target marathons or they aren't real runners".
That being said, either way you do this you have ~30 weeks to train for the race, which is a solid chunk of time. Coming off your low mileage base it would probably be a good idea to spend the first 12 weeks of that just building mostly easy mileage.
These runs should not be hard, and you should be definitely feeling like you could keep going for a long ways more afterwards. If you finish the run feeling like you didn't actually do a workout, you are doing it correctly.
Were you planning to just jump into running every day, or have you been doing so already? Starting out, I would say that you should keep one rest day to try to help avoid injury. You can turn that into another short easy day as your body adjusts to higher mileage.
Adding 5 minutes every other day doesn't sound like the worst idea in the world to me, but I personally don't like overly specific time prescriptions like that. It just never feels realistic to me. When I go out to run, I'm generally going to run a loop, or some out and back, or a couple loops, or whatever. It's going to be a set course, and I'll finish back where I started. If I'm going a bit slower, or take a different route, I'm not just going to stop running half a mile from home because "my run time is up".
Be more flexible about your distances. Try not to overdo it, but think of your run goals as more of a range "40 - 50 minute run" or "5 - 6 mile run" rather than "Exactly 45 minute run". Stressing out over the exact distances or times there is never going to pay off.
I would recomend you take a look at any or all of these books:
Pete Pfitzinger "Advanced Marathoning"
Jack Daniels' "Running Formula"
Pete Pfitzinger's "Faster Road Racing"
I have only read the first two, but I have heard the third recomended on here many times, and it aparently has specific base building plans that you could use for the first 12 weeks.
After those 12 weeks, Pfitz' Advanced Marathoning has 18 week marathon training plans that are popular on here, and are very specific about what you run each day. Daniels' Running Formula also has a number of marathon plans, but they are a little more free form (which I prefer).
I'd recommend you to buy and read either this or this book. It'll explain it very well. But the tl;dr is Different intensities work different systems in your body and allow for different adaptations. Also, if you run too fast you will get tired earlier and can't run more. And you need to run more.