OMG... I am basically you plus 3 kids! I even work for a County Office of Ed! I just started the “running” last week. I was walking 3-4 miles a day all through the month of May because I was scared of starting all gung ho and getting injured and quitting. During that month my knees started popping, so I bought new shoes and several knee braces to figure out which worked best for me (physix gear compression sleeve).
With the running, it’s only been a week but so far the thing that helped is something I learned going through the divorce - EASY DOES IT. You know those old geezer runners you see shuffling along? Yeah, that’s going to be me right now, enjoying the fact that I’m doing something good for myself and bumpin my Pandora “workout hits” playlist. Speed and strength will come in time if we just keep going. Good Luck to you!!!