That sis a great idea but it would be good for you to go and work in a herbal store to know the ins and outs of the business before opening your own. You are in the right track. Opening a shop with lack of experience and putting your faith on someone else to run it with minimal knowlegde is not wise. If I were you I would start from the bottom up. Otherwise good luck
I think opening up your own business is a good idea! Although it is obviously not required, getting a business degree of some sort would do some good. Also, remember that opening up your own business means working practically 20 hours a day for the first few years. You will be in debt and you will not get enough sleep. Also, come up with a business plan - you may need to take out a loan A business degree would be the best route to go after high school.
do your research! It might be great! write a biz plan