can I use mini iPad (wifi only) and a mobile hotspot? please include all details as though explaining to a 4 year old

I would appreciate any recommendations for models, how to purchase, information re: whether data plans are needed, etc. I live overseas and need this while in the States. Do not have an iPhone or other plan that I could connect my device to. mini iPad purchased @ end of 2012, if that matters.

I know I need to purchase something--likely it will only work in the States, but are there any that work globally?

THANK YOU in advance for your help and time.