Know your customer and stay focused on that.
Location is very very important unless you are a brewery or a destination. Cheap rent is not always a good thing, and neither is overpaying.
Coin drop pinball is a loss leader. Alcohol is where all the money is. So price your games accordingly. What will draw people in and keep them drinking while not losing money on the machines and maintenance. Pinheads don't spend money and their game times are much longer than gen pop. You want gen pop, and lots of them.
You need food to keep people longer. It is a loss leader too.
Building a solid base can take years of weekly events and outreach. Do you have the working capital for that? BTW Stern Army doesn't really help attract people.
Will this be your main income or a hobby to start?
I opened one last year. If you want the skinny, PM me with your contact info.