Good to see this dweeby thread emerge. We may have someone else to discuss after the 30th but if not we can sit and admire the size of each other's cucumbers (ooh missus).
We got an allotment in 2021 after home-working allowed us more time on it. With an upcoming house move, I'm afraid it will be going but we will be acquiring a bigger garden to get started in. From being more engaged with home growing, you learn some things are fool proof and bomb proof - tomatoes, cucumbers, courgettes, strawberries, some things are grown to last into the winter months (Crown Prince squashes did well. I still have one stored in the cupboard) and others are temperamental - we had no real luck with raspberries or gooseberries last year.
A few bits of my advice for what they're worth.
1. Grow things that are expensive to buy in the supermarket. A 200g box of gooseberries for example will probably cost £2.50. Grow your own and you save there massively since one plant will give you loads. It's why I have never really bothered with growing onions and garlic that cost pennies whereas blueberries, strawberries and raspberries are extortionate in the supermarket (and you end up with crap 'Elsanta' variety strawberries too).
2. Grow varieties that you wouldn't find elsewhere. Commercial growing is for high yield and therefore profit so the variety types tend to be limited. Home growing is for your own pleasure. We've grown yellow disc patty pan squashes recently alongside our regular courgettes and they produce fewer fruits but with a different texture so offer something different. Websites like 'Plants of Distinction' sell loads of heritage seeds for fruit and veg that has fallen out of favour so you can find all sorts of unusual and different varieties that are unviable for a farmer to grow but easily produce enough food to satisfy a family.
3. If you have surplus stuff, see if a food bank will take it. Our allotment committee joined a collective of allotments who provided surplus veg to a local food bank or either divvied it out or made some home cooked dishes for people. Well worth doing if you can.
Oh, and for the city dwellers, Rectory Farm's asparagus patch opens tomorrow too. Easily the cheapest place to pick asparagus around Oxford.