I do marketing and a couple of my clients have on line stores.
It takes a LOT of advertising, direct mail, Facebook, Snap Chat, and even radio to drive customers to a website, and even then you are not guaranteed they will buy anything.
So the money you save on renting a location on a well traveled street ( Maybe $3000 a month)..you will have to spend that on advertising your business in order to be successful. If you do not want to pay a person like me to do that for you, then you should get a book on Search Engine Optimization and read it cover to cover.
I'm not saying that you can't do it, I'm just saying that it is not going to be as easy as it sounds.
But if you stick with it and sell tings that people want...(the phone cases...you can buy a nice one for $5 or less at the Dollar store...and you can pick them up for 50 cents at yard sales. I got one free with some deodorant...so do not sell those. Same for mugs. I have a cabinet full of mugs given to me for some reason or another...usually by some salesperson trying to get my business. Everybody I know has a cabinet full of mugs. try to sell something more unique for a successful store)
Finally...hire a lawyer to make you a business plan.