best of luck, the first step is making the decision to do something, so kudos!
I weighed 225lbs (102kg) in 2013 and had gone up and down over a number of years earlier when I did take exercise more seriously (I had gone from 225lbs down to 165 once previously before getting running injuries and gaining weight). We had just moved to a place that was right by a bike path, and I made the decision to start riding my old mountain bike on the path, since I was a bit intimidated by the roads.
I ended up hating the mtb but I stuck with it for a bit and in Oct 2013 got a hybrid that was faster for me than the mtb. During that fall and winter I rode both outside and indoors on a cheap trainer and between watching what I ate (I didn’t follow any particular “diet” just ate what I normally did except for less of it) and gradually increasing the amount of time on the bike I lost 70lbs (31kg), and have mostly kept it off. Within a year of starting with the MTB, I had done a road race and a 100mile ride.
I know it’s said weight loss comes from eating and not exercising, and that’s certainly true, but for me I’ve had to do both diligently, so I always advocate for people to take exercising as seriously as diet. Maybe it comes from being an athletic person growing up, but I find I get more zoned in when I’m thinking and acting like an athlete rather than someone who is just doing some physical activity. But as a first step on exercise, I’d forget the intensity and try as much as you can to increase the amount of time you spend riding.
Again, good luck to you (and to any others looking to make a change!)