quoting earlier ac:
This!
It takes years to cultivate a sustainable organic garden that will actually be able to feed you...year after year. Lots of knowledge to acquire.
Have a back-up plan in place as you work towards sustainability. IF things get really bad have some seeds other than heirloom handy….and a little fertilizer. These things may save your life as you learn……

avoid GMO seeds!!! Nature instinctively knows that these seeds are unnatural/incomplete and if you DO NOT SPRAY FOR PESTS AND DISEASES, pests and diseases will consume them. That is the very definable job of pests and diseases, to cull sick plants and organisms within nature...

as far as "Lots of knowledge to aquire" goes, that's why we are all here sharing:)