Here are some free training plans that can be used to help preparing for races. Each plan is unique to you as a runner so take time to read through each plan and match it to your goals, making sure it works with the level you are striving to achieve.
Hal Higdon beginner to advanced plans. https://www.halhigdon.com/
Runners world based on times https://www.runnersworld.com/uk/training/marathon/a776459/marathon-training-plans
Boston Marathon training plans https://www.baa.org/races/boston-marathon/boston-marathon-training
Strava https://www.strava.com/training-plans/running
