First- great news about becoming a runner! When you sign up for a race, it’s official, you are a runner. I’ll be brief since a lot has been covered. 1. Not familiar with this exact machine but if it can be used just as a treadmill, you’re fine. I’ve trained for marathons using a treadmill for at least half of my training runs. Set it to a 1% incline to better mimic the road. If it’s more of an elliptical, wait until a better weather day and run outside. 2. Yoga. Great for runners. There are so many free “classes” on YouTube now so you can do yoga at home. 3. See if there is a specific training plan out there online. 4. Never done, but check out timing and start/ finish areas for each race. Logistics may be difficult.
Slight correction… If you run period you’re a runner. It matters not how long you run or how fast you run or if you ever sign up for a race. If you run, you are a runner.