Half an acre should produce all you need for the year but have you free water, shade, shelter from the wind and decent soil. You will need to feed the ground so maybe invest in some livestock or poultry to produce muck that you can chuck on the compost. Oh - by the way I found the growing the easy part. It's the processing or storrage that takes time, money and space. We have a cellar for spuds, freezers and preserve what we can - any surplus can be traded.
Good luck ! There are some very very experienced and knowledgable veg growers on this site who can help with specific questions.