I've told my story elsewhere on this board, so I won't repeat it here, but ... 112 kg and pre-diabetic at age 60, not good. I'd always loved cycling, but had ME at 40 and never got back to it after I recovered. I bought an electric bike and started commuting to work (25 hilly miles round trip, did it every other day). The first few trips nearly killed me, but I stuck with it and it got easier. Then I refurbed my old mountain bike and started going for short rides at weekends on that. Still hilly, and that nearly killed me all over again, but I found when I got back on the ebike after a few times on the MTB I had Superman legs and the commute suddenly became much easier. That happened very quickly, almost over a weekend. I have bought a hybrid and am aiming now to commute by 'proper' bike when the clocks change. With the cycling and some diet changes (cutting out sugar, watching the calories with MyFitnessPal, highly recommended) I lost 3.5 stone in six months. I am now fitter than I have been for many years, and I owe it to the ebike and a lot of determination.
Well done making a start. I'd agree with everything said above. Don't do so much it becomes a chore, but get out on the bike whenever you can for short rides, and increase as the fitness improves. It should always be fun.