I'd like to buy a plot of land for trying to live off the grid. However I'm struggling to find what I can plant in certain regions. I'm in Europe and I need to check what I can plant in each region (from 7 to 10). How can I check such information, mainly for fruit and vegetable?
I like the idea of living off the grid, but as you can read from the comments your question is too broad to get one straight answer. However, I can direct you to some info, that might be helpful.
Like some people commented already, hardiness zone info is not important for most annual crops. So a vegetable garden can be grown anywhere with fertile soil and irrigation. For fruit trees for example, or other perennials, the EU site for agriculture might be useful. There you can see which crop/fruit is grown in which country. It can be used as indication, not more than that. It tells you for instance that growing oranges is not feasible in Belgium, but is in Portugal.
Growing your own food is of course just a part of living off the grid.