I grew up having to grow pretty much everything we ate (by necessity as you couldn’t buy anything in stores). And whatever we didn’t grow ourselves we helped relatives or neighbors with and shared in harvest.

I personally don’t understand the appeal of going back to that. I’m so glad I can just buy whatever I want at the grocery store these days and don’t need to spend all my free time on harvesting calories.

Step one is to quit your day job.

Step two is to put in ~12 hours a day, 7 days a week of work into homesteading.

Step three is to dip on your savings to buy farming equipment, consumable inputs, and groceries for the remaining half of your food that you won't be able to grow yourself.

If you'd like to try before you buy, my parents' homestead up in Canada could always use another pair of hands. Money's a bit tight, but they can pay you with food and a couch to sleep on. You'll have to share the room with ~15-30 baby chicks, though. You'll quickly get used to the smell.

I understand that this won't give you a vertical garden, but unlike a vertical garden, it will go most of the way to meeting your daily caloric and nutritional needs.

It will never cover your whole diet, but it is a good way of growing some of it yourself. And that's not as time intensive as the other commenter says. If you use soil, have the lights on a timer and use auto-irrigation, it's pretty much hands free. A few weekends to set up, then months of marveling at how plant life works heh.

I think it's really hard to grow most of your food with little effort, but you can go start with FarmBot

See here for yield estimates https://farm.bot/pages/yield With 18m^2 you can only get 175 calories/day which should be less than 10% of your diet.

That depends on your diet and place.