Some ideas I find online are like sticking a water bottle in or with a fabric wick to water soil or pots. This would be highly impractical on such a large area.

Seen some interesting ideas that work for raised beds, but I don't really have the budget or materials to make raised beds without losing most of my space in the process.

Water reservoirs that you can top up sound appealing if that is possible. I don't mind quite a bit of work or a lot of digging. But I don't want something that will cost lots of money. Soaker hoses would cost 3 figures to cover an area this large, plus we are not allowed to leave hoses unattended.

I don't have a car to transport heavy materials and my plot isn't by the road so even if I did it would be impractical.