Need help with regimen to improve

I'm 5'9 183ish pounds. I'm about 16% body fat. I am not underestimating my bodyfat. I have a labor job that requires lifting and cardio and i hit weights hard 6 days a week. I recover just fine.

I started running twice a week.... 1 week ago lol

First try: 10.2km/hr pace. ran 1km. complete break, then .62km

Second: 17km 30 seconds then 4km for a couple minutes and continue that until i hit 1.62km

third (yesterday): ran at 8.5km for a mile/1.62km no breaks!

I have zero ifea how to structure cardio, but i'd like to run a sub 7 mile one day like i did as a small kid. Just doing this to improve overall heart health and oxygen intake.

Idk if i need to give more details, but any advice on how often to train? When to increase intensity etc