New Scenario

[Steve]

One square mile is 640 acres. 100 people per square mile gives them 6.4 acres each.

That's just me being pedantic. In reality much of the land is worthless, poor soil, too steep, waterlogged, covered in tarmac etc., etc.. Forget city "openspaces", your crops will be gone as soon as they look edible.

If you're a city / town dweller perhaps your best course would be to head for the countryside and make yourself available as a labourer, farmers will be missing those huge tractors so an extra pair of hands could be welcome, you get to learn the business and can bugger off to do your own thing later on.