What do you think would be best to live out of?

the goal is to spend as little as possible upfront and in the long term on recurring fees
I plan to work and save up to build something and then go back to being a self sustained NEET living off centrelink ($500AUD a fortnight)
I have 16k saved now and hoping to set something up with 30-40k

my uncle has a gigantic 7.5km2 cattle farm and has agreed to let our family move onto his land
considering just building something and living in it illegally, rather than dealing with the council and budling permits etc.
something moveable like a van or trailer also has a lot of benefits like traveling and being harder to get fucked over, but is it enough space?

all of the options would be off grid using solar, water tanks and compost/septic tank toilets