I have had quite a few exercise machines in my life, here's my advise. Don't go out and spend big money right away, buy a quality used machine if you can. I always considered and kind of aerobic type of equipment as temporary, I would use it for six months, look at it for another six months, than sell it and buy something different.
If you fall in love with a type of machine or workout only then should you consider buying something high end.
Another thing is don't initially buy a subscription to an online workout program. Just go onto YouTube and find workout videos for whatever machine you have. I do cycling videos and like HIIT videos for my workouts, there's variety and it helps me avoid boredom.