I have no idea where I started, Flo. I think some elememts were always there from childhood - following my Dad round his veg patch and greenhouse, helping my stepmother (who fortuitously was a chef) in the kitchen. Although most of that, apart from cooking (I've never liked the taste or used ready meals), got forgotten when I lived in London, all of it returned when I had my own child and we go our first house - a 2 up, 2 down terraced house with a communal back yard. We grew herbs in an old sink by the back door and had a couple of fruit trees in pots. Unfortunately the trees got pinched.
I think the sheer joy of cooking and/or eating something you've grown yourself is one of the most satisfying things imaginable. I think it's something you can do whether you live in a mansion or a highrise flat - there's always something you can grow, even on the smallest windowsill - even north facing ones! You can, and I have, start with just a jam jar a pair of old tights and some sprouting seeds. Before you know it you're sprouting 5-6 different seeds or pulses and wanting to know how they grow/taste etc as thet get bigger. You can even get carrot seeds that grow the tastiest little round carrots that can be grown in a pot on a windowsill.
I've never been able to keep a houseplant alive for more than a few months, at most, but I've got calamondins growing on my windowsill that have been in fruit more or less continuously for several years. We freeze the fruits as we pick them and make a delicious marmalade hen we've got sufficient. That's the other big thing for me - preserving produce. Even if you can't grow much, you can often find cheap fruit and veg at the market, or supermarket that you can preserve for leaner times - a cheap cabbage and a tablespoon of salt will give you sauerkraut to dig into later on when veg are more expensive. Cheap fruit can be preserved through jam making etc. Home grown, bottled tomatoes are the best thing ever!
Climate change has noticeably, over the last 4-5 years, changed what we can grow up here, so we've had to curtail a lot of our vegetable gardening in favour of perennials that will provide us with food. That had always been my plan - my food forest - but the weather has rather spurred this on. We still have a small veg patch but certainly not big enough to feed us. Hopefully we'll have a dome too before long. In the meantime we have a small "greenhouse" and the SW facing windowsills.
But we're all about the Ish here - doing what we can.