You can find reasonably priced treadmills online, even if it's just a small walking pad for a couple hundred bucks. Start with small habits and build from there. If you want any more help, I'm a CPT & CNC and can give you some more tips or send you some guides
I have a walking pad and a Tempo Studio and work out in the early mornings before I come back. It was a game changer and the only way I could get my activity in on a consistant basis.
i use the at home stair stepper from tiktok :)