There are a lot of parts of the world where it is possible to subsistence farm. The quickest and easiest way to see if a region is friendly to farming is to pull up Google Maps, look at the area, and see if the area is carpeted with farms. If, outside the cities, the vast majority of the land is occupied by farms, then that area is going to be very friendly to subsistence farming, and even a novice should be able to make a passable go at supplying his/her food needs with farming, assuming access to educational and information resources and plenty of time to devote to it.
For an example of a part of the world that is very friendly to farming, look at a satellite image of rural parts of most US Midestern States (Illinois, Iowa, Indiana). It'll look like a patchwork quilt where all the patches are individual farms.