There's no roadmap for success with these kinds of things.
To start a nanotechnology company, you first need some kind of patentable technology. You can acquire this either by inventing it yourself, or by purchasing it from someone else who has. You could also try developing something that doesn't have a patent, but the issue there is that if you're even moderately successful, there's nothing to stop the bigger companies from taking your ideas and developing them on their own.
Getting to the point where you have some kind of technology to develop is the first major hurdle. Often what happens is that you have someone who studies these things, gets an idea and then pursues it academically for a while, and then once it becomes clear that there's potential to bring it to market the inventor starts to figure out how that is done. And there are a lot of different avenues to get into nanotechnology: materials science, chemistry, physics, biochemistry, chemical engineering, etc. Depending on the level that you're at right now, the best way to start is to get an education first - pursue a university degree and probably a graduate degree. The business side of things tends to be a lot easier for an educated scientist to pick up than the science side of things is for business people to pick up.
Also, please try to type properly with punctuation and capitalization.
Do you want to be an entrepreneur, a researcher, or a medical doctor?
A MD works with people.
A researcher researches patentable technology.
As an entrepreneur you need to be a people's person and have an instinct for markets and investors.
I have been told by several scientist that if they went back in time, they had magical entrepreneuring skills, they could have become milionaires by developing patentable technology from the knowledge/technology that they helped discover in their research group.
Hey, it would be great if I was an MD, great interacting with people (as all MDs are!), getting a positive vibe from their negative experiences and my positive effect on it, have actual job safety, gain respect and prestige in the eyes of the average person that no scientist in their messy shed of a non-glamorous lab would ever get, unless they win a Nobel prize.
Then it would also nice to be an actual doctor, not just a medical doctor.
Then it would also be great if I can be the new Elon Musk.
But it's not gonna happen for me.
It is just that the quickest and most straightforward way of becoming someone who does research in nano medicine won't involve getting an MD. You learn completely different things. That for applied nano medicine you need to work together with an MD, that's a different issue. Once you have something that works on paper, works in vitro, works in cell lines, works in test animals, then you go to the next step. But when you get to animal experimentation, the first person that came up with the whole fundamental idea is likely working on a new fundamental idea and only side-ways involved with the animal trial part.
As for entrepreneurship, that's a whole can of worms in itself. You don't even need to know any science or medicine. Just have the money and leadership to hire people that do.