Okay, this is more or less the simplest exercise you can do, mentally and physically, if your legs are more or less ok. It provides just enough aerobic exercise, and most importantly, it doesn't leave you with the burned out "I never want to do that again" feeling that straight running does. Here's the trick: You run for a minute, then you walk for a minute. Repeat ten times. That's it. Forever. You don't bother with increasing your time or distance or interval spacing. Keep it simple. The goal is to get out there and do it. As you increase your aerobic capacity you will find yourself running a little faster. That's good. If you start off with the smallest of shuffles for the running that's fine.
You should find that you become a little short of breath during the running sections. That's what you want, just not too much. I use an app on my Apple Watch called Intervals to help me keep track, and it shows that my heart rate gets up to around 150 or more towards the end of the workout. You can also use it on your phone, or just look at a regular watch and keep track in your head.
Even doing this only twice a week helps. No need to do it every day, but I suspect four to five times a week is ideal.