Don't buy your dream bike as your first bike.
Your first bike should be something small, light, old, and cheap, but roadworthy. Something you'll ride, but have no long term attachment to.
Cheap learner bikes can usually be sold on for little or no financial loss as long as you don't completely wreck them.
Dirt bikes and close relatives (not enormous ADV barges) are great first bikes.
You may discover after getting some experience that what you actually want, isn't what you thought.
