With everything I've ever learned, I've had to learn to walk before I could run. Examples:
And so on. If you've ever done anything that requires any skill, you know that you have to master the basics before you can do the hard stuff. Is it the same or different with businesses?
If it's not the same with business, why not?
If it is the same with business, what's a good way to get started? Would it make sense to start with a small "practice" business simply for the sake of seeing encouraging results? (Example: lemonade stand)
One difference I see between the skills you've listed and running a business is the irreducible complexity inherent in the latter.
The mere act of playing guitar makes one a guitar player, even if you've only learned some simple licks. If you can cook scrambled eggs, you can cook.*
But to be an entrepreneur -- even a lemonade stand entrepreneur -- requires some level of competency in lots of sub-skills -- product development, marketing, operations, etc. etc.
There's also a "time" factor. The act of guitar playing can be expressed in a five minute performance. Being an entrepreneur is an ongoing, twisting and winding path that unfolds over months and years.
I think this all puts a lot of value on giving yourself wide and varied real world experiences to learn from, whether in an apprentice role or off on your own trying to make a business fly. Not against the book/training route by any means, but I'd view those as supplementary to 'learning by doing.'
*To be clear, there's a world of difference between expert and novice musicians, chefs, etc. But the barrier of entry to becoming a "novice entrepreneur" seems much higher to me.
Two paths come to my mind. Education or Mentorship.
I reduce anyone's chances to kicking off a successful, growth business (meaning not a boutique or hot dog stand) to three core things: Vision, Execution and Luck.
Now, with those skills you list above, neither the first nor the last applies. It's all just will/desire that fuels the continued practice of the skill. IOW, it's just about execution.
A corollary is that you can't "start small" with Vision or Luck. Starting small, to me, simply means reducing the level and types of skills needed by reducing the size and end goal of the startup, as per cfrech's observation that entrepreneurs need to rely on a wide breadth of skills.
So, in a sense, you can "start small", or you could be mentored, or you could try to join a VC-type group and indirectly live startups. But, I don't think anything gained translates into distinctly better chances at success fo you in your first startup, except maybe the mentoring one, because of those two other factors intrinsic to any individual and his/her startup.
PS: This post, where I say you can start small, may seem to contradict my other answer to you, but it doesn't. You can start small, but IMO don't see the point of it. I guess I am more of a "go big or go home" type. This totally realize may not apply to you. :)
cfrech is right that there are a lot of skills you have to master and execute well to run a successful business. So start the learning curve by mastering them one by one:
Find work that will cause you to develop these skills. As Tim suggests, be proactive about taking on responsibility as an employee and hang out and learn from people who are doing things you are interested in.
This way you can develop the skills you need as well as take time to sort out what your own goals and aspirations are.