Zucchini and curcurbits in general are usually no problem if the fruit is off the ground, so trellising sounds like a good idea. Heavy fruit like pumpkins can’t be trellised and take up a shittonne of room, so might not be the best use of space. If you do have a try at pumpkins you might need to put a tile or plank put under each fruit to keep it off the ground.
Root veg would be better in pots or similar. As I didn’t have room or good soil for spuds in East Brunswick, I grew spuds in car tyres stacked up on a concrete base. Made harvesting easy too as all I had to do was pull each tyre off in turn and fumble out the spuds. Very very productive way to grow spuds. Round carrots & beetroot went in milk crates lined with shademesh - these worked very well and also worked for leeks and silverbeet. I am too cheap to buy large pots from the green store. I found 1 bag of potting mix fitted nicely in 1 milkcrate too which made planning easier. Milk crate gardens did need extra watering in summer as they did dry out a lot if I didn’t watch them. One benefit was they were easy to move about in accordance with the weather/sunlight. I’ve tried using growbags, but I find them a bit heavy to move about. They do hold a lot of soil so could be good for big carrots etc that need a deep soil bed without lumps in it.
I was considering the tiny sugar pumpkins that wouldn’t be very heavy, or snow peas but chose some zucchini seeds. I’m thinking to stake them up or maybe improvise a lattice.
The milk crate pots are ingenious. I’d probably forget to water or have to bring them inside though so maybe not… I wouldn’t be able to lift the grow bags or the tyres but these are some good ideas
For me watering was a once a week sport. In very dry hot weather I’d kick the milk crates together to reduce evaporation but not much more than that. Peas/beans are reliable, productive and would be safe but would need a lattice of something to grow up. Lengths of string tied to the fence would do and be removable if you left the place.
Fun fact: beetroot leaves are delicious in salad when small and young. Can be cooked like spinach too. I sow beetroot pretty thickly and harvest most of them for leaves, only leaving a few well spaced out to make roots.