I’d say the beginner plan is a good starting point for you, then. You’re still young enough to reap the benefits of sticking with the system for years. The people I’ve read about who had success with this system used it for years.
I’ve used it more or less for 3 years. I’ve had to make some adaptations to it because I spent some time doing ultras. I’m back doing 5 km/10km now and following the Advaned 10km schedule. Recent races include a sub 35 km and a 17ish 5 km. I feel like the basic structure of the schedule is great, but sometimes life gets in the way, so some accommodations must be made. There is some room to emphasize different paces and workouts depending on where you are in your season that you’ll learn as you go.
Things I really like about the system are that the workouts are mainly fartlek, so you can do them almost anywhere. For example, the structured fartlek takes only 20 minutes but it works several systems (neuromuscular, cardiovascular, lactic). In a pinch, I can take 40 minutes at lunch and get in an effective workout. It’s weird to think a run that short can accomplish so much, but it really is the most effective workout I’ve found.
Things I don’t like are that there are only 2 easy days each week. If you need more recovery, you could always make it a 9-day “week” and build in more easy runs. I feel like since I know I have another workout coming soon, I keep myself in check. Every run has a purpose, so to speak. I could see a person getting bored with the same few workouts. I haven’t yet, but I try to keep things fresh by running new routes, finding new training partners, etc. When prepping for a marathon, I feel like it’s important to emphasize hard long runs, and the schedule doesn’t mention this. It’s kind of sort of implied, but it would be better if it were spelled out.
Ok, I hope that makes sense. This is all kind of stream-of-consciences after a long day.