- are there any Bitcoin events in your region?
- are there LocalBitcoins (or other "marketplace" sites) ads for your city or region?
- is there already someone near you at https://coinmap.org?
Very likely, if you're not living in a "Bitcoin hotspot", then the Bitcoin user base in you region will be pretty small. In a ordinary one-million-inhabitants city you can expect some 500-1000 users at most. If your shop is well connected with local and regional traffic (trains, highways ...) then you could try to get clients from neighboring cities, because a real Bitcoiner will travel some time to use his precious digital gold
The reason is that I am living in a small city where the people are of average life slandered Therefor it is difficult for me to estimate the local bitcoin market.