Hi emalee, if you have an alternative shop in your town they may have kits and stencils, or be able to tell you more about them.
The only reason I can think that henna could be a bit dodgy was if it was mixed with a poisonous plant, as henna tattooing doesn't pierce your skin or anything. An allergic reaction is possible, but quite rare.
All I would say is steer clear of henna on holiday, because reports of dodgy materials are often heard!
I used to henna all the time, and I loved having hennaed feet :)