Yes. Many beginners training for a marathon will take 4-6 months to train safely for their first race. Athletes who have (essentially) never run before, will be closer to 6 months, where those with some 5k experience might be able to shorten it to 4. A combination of running, walking and cross training allow for someone who has little to no experience train effectively in that time period. Naturally, nothing worth doing is easy, so don't confuse possible and simple with easy - as training for any marathon will have its physical challenges. Training will take a toll, so it's important for any beginner to learn to properly rest, recover, stretch, hydrate and fuel their body throughout training.