I like the IFit program, I think it works on Norditrack and Proform treadmills. It’s helps beat the boredom when running on a treadmill. I have a Nordictrack C2950. Lots of used equipment can be found on offerup and places like that.

I didn’t necessarily “train” for a marathon. I was planning on running one and when I was able to run 20 miles comfortably, I felt like I was ready. At mm 22 it started getting hard, at 24 I wanted to quit but I finished and I’m going to run another. This was 10 months after a knee surgery. Just be honest with yourself, if you think you can do it, you’ll be fine.