How competitive are you? I have to say, I started moving a bit more with a Fitbit, but an Apple Watch was revolutionary. I was already exercising regularly (I'd managed to change habits but also see a PT fortnightly, and if I don't do stuff in between our sessions they're REALLY hard, and not as much use), but having daily goals, monthly goals, various other goals, competitions against friends, trying to outdo PBs etc etc has been so motivating.
I'm nearly 44 so not much older, but I've really noticed the last couple of years how much harder it is to maintain muscle density and keep the weight off, so I'd really encourage getting into good habits now.
So other than the Apple Watch and PT stuff (I work a 4 day week, so see him on my day off, but he sees plenty of clients before their work day starts), I go to an evening weekly circuits class with friends (set up a WhatsApp group to chivvy them along each week, so there should always be someone to go with), go to yoga once a week after work (studio in my village, so easy to get to, and just lovely, so I want to go), then might go for a run, or do a Fitness Blender session at home (I have a few weights and stuff at home). If I've not done anything, and not got much time, or it's dark, I'll just walk on the treadmill at home for half an hour after dinner and the kids are in bed. DH has just bought a spinning bike too, so I might give that a whirl.
I've genuinely got to a point now where I get a bit angsty if I've not moved in some way each day, and I NEVER used to feel like that. However, it would be very easy to skip a few days and then slip into old habits. My watch then nudges me every day, so it's a great motivator.
The hardest bit is getting out the door, but once you've done that, I don't think you'd regret it. Good luck, keep us posted!