Biggest tip I have as someone who has been a runner in both peak form and as a fatty, start off slow. Youre more likely to stick to it if you arent gasping for air the entire time. Also, set goals in time, not distance. Its really easy to add 20% more minutes to your run every week vs having to think about distance. 10 minutes doubles to 20 minutes like after 5 or 6 weeks. If you cant run the entirety of your time without stopping, youre going too fast.