Preparing for my first Marathon - Chicago 2026

I decided to go for it and get into running as of late. Seeing the excitement of the Chicago Marathon got to me. I've secured a guaranteed spot for 2026! I'm not sure exactly what to learn here but I am hoping to get some general guidance on how to prepare over the next year, tips, diet, staying healthy etc. Also if anyone wants an amateur in their local run club, I'm open to that! Any and all feedback is appreciated

So far I've downloaded the Nike Running app, Strava and am finding the right shoes (leaning towards Brooks). I can do a sustained run of about 1.5-3 miles at this time, need to start significantly improving my cardio/endurance.

About me: M28, washed up D1 Athlete (Swimming), 6'2'' 195lbs, living Gold Coast/Old Town. Also booked to run the Bank of America series in 2026 (Shamrock & Half Marathon)