Family advice: life after 40 for most people is about family and the children (that they presumably had in their 20s and 30s)
Biz advice: People will happily pay you much much less than your worth if you put up with it.
Checkout /r/fitness on Reddit for some example beginner routines that were helpful when I first started out.
It's really easy to get overloaded with information when first starting out. Keep it simple, figure out what works for you.
I love heavy lifting so I focus on squats, deadlifts, bench press, etc but I also make sure I do at least 30-60 minutes of cardio to finish off a session at the gym to keep my heart in good shape too.
I have read real world stories of people starting running at the age of 60+ and finishing marathons.
I urge you to get off your ass and embrace active lifestyle. You will not regret it.
Edit: In particular, my biggest problem regarding getting fit was some flexibility that I lost in certain joints, living an inactive life. That held me back more than fat loss/muscle growth.
Just focus on the process and enjoy the ride, I guess.
All I'll say is that its worth a shot. Its really nice to be fit, both physiologically, because it feels good and because you become more attractive.