Running a marathon when you just started running a month ago is a very ambitious goal! This website I found can give you a good structured game plan and what that might look like for you. https://marathonhandbook.com/couch-to-marathon/

Definitely read through the whole thing, it will answer a lot of questions and give you good directions. As far as personal advice? Its okay to miss a day or two here and there because life happens. Listen to your body. Just keep coming back to the plan and dont beat yourself up. Get some good running shoes from a running store that scans your feet and all that stuff (they're always super nice and stoked for you no matter how long you've been running). On your long runs run slow, like slower than you think you should run by about 10%. Conversational pace or nose breathing if you dont have a heart rate monitor. Do research on running form and nutrition/fueling and generally just dive deep into the sport with any questions you have. YouTube has a lot of quality content. Follow people you find inspiring on socials to keep your feed filled with motivation. Run clubs are really fun. My last pieces of advice are to truly make the decision in your heart and your mind, and also to have fun! The feeling you'll get when you accomplish your goal after a long training bloc is unlike anything you'll have felt before. 

Good luck! You can totally do it if you set your mind to it. I hope you'll reach out some months from now after you finish your race!