* I hired a personal trainer. Actually, two of them, scheduled on different days, to reduce the chance that I would saddle myself with a bad one and not know it. After 2 months I let go of the least effective trainer. The trainer(s) were huge at first because having an appointment with someone helped me actually get off my ass and show up, my own willpower alone was always insufficient in the past. They also exposed me to a variety of exercises which is how I learned that I really enjoyed weight lifting (and some other exercises, not so much). Nowadays I just have the one guy once a week doing form checks.

* I joined a very nice gym near my office, again as a motivator. It's easier to attach one habit to another habit, and the habit of going to work is pretty ingrained, so "walk across the street for one more appointment" turned getting into the gym from something hard to something that was basically automatic. My workout is my favorite part of the week now because my gym also has a great jacuzzi and afterwards I get to plop into the jacuzzi, veg out and catch up on podcasts.

* In terms of the "technology" around weight lifting specifically. I'll triple emphasize just hiring a good trainer and just following their instructions at first. But once I started engaging my own brain, I found A) Correct protein/macro intake was bigger than everything else in terms of getting results. Get your daily protein to where it needs to be (which is freakishly high) and same goes for calories (depends on your current body type and intake). B) You don't have to push hard on increasing weight at the beginning at all, nor worry much about how many reps you do, just do what is fun and safe and do it regularly. C) For further education the book Starting Strength and the Fitness Wiki maintained by Reddit's r/fitness are really good. They recommend similar beginner workouts and as an out of shape guy, you can basically start on these immediately as long as you're getting regular form checks and sticking to low weights. (I actually was so weak I had to start with just the bar or even dumbbell variants... once I started pigging out on chicken and whey, that changed very fast, increasing how much I was lifting got easier, and within a couple months I had muscles everywhere.)

Make sure you ramp load gradually if you have lifted in the past, your muscle memory can return faster than your connective tissue strength leading to injury risk if you stack the weight aggressively.

This! Dealing with this right now :(

The way I am managing to build my habit: Only do group sessions. If you want to go fast you go alone, but if you want to go far you go together. I know that group sessions are the only thing that give me enough structure to continue.

So maybe it will help you get started as it did for me? Personally I went to a fairly expensive gym so the groups are small. This to minimise risk of injury. Try it if you can afford it.

Start with push-ups. They're fast and require nothing but a flat surface. You can always transition to lifting weights later.

Start today, ideally right now. Seriously. It's your only chance. Tomorrow there'll be an even better reason not to.

Don't worry about initial quantity. You can start with two push-ups, that's fine. It'll take ten seconds if as much.

Repeat every day.

When you feel it got too easy, increment by one starting the following day, not at the moment.

I tried 3 times a week or whatever, and every day you'll find some excuse to push exercising to the morrow.

But doing exactly the same routine every day was key. Then the routine evolves with time, but it's almost always the same routine. I started with a few pushups, then added burpees, then I bought some weights and added a few movements, then I started running 300m a day the first week, and augmented gradually until I ran 42 km every single week.

Years ago, I used a trainer in a gym to kickstart a plan, and I found it very useful.