Hopefuls often ask there is somewhere out there they can stay for free indefinitely. There are problems with long-term stays in general, even if you do find a place that allows it.
Assuming that's all covered, let's consider the possibilities.
The only real unlimited camping is Slab City. It's not everyone's cup of tea and gets unbearably hot in summer.
Slabbers police their own and may not suffer fools gladly.
It is conceivable there are friends/family willing to donate a backyard or driveway. But if OP had that option they wouldn't be asking the question.
Note that even if the friend/neighbor allows it the city or neighbors may object.
There are RV parks with long-term rates but they cost money. Many don't take campervans or anything other than relatively new commercially-built RVs. Is your shore power setup already built?
There are LTVA you can stay at for months on end but they cost money.
You can stealth camp in cities but you will need to be discreet and have many rotating spots.
You can boondock on public lands, usually in 14-day stretches.
Buying land is not free, of course. And people are amazed to find out that citys/towns/counties often have rules governing what you can do on your own land. Research local laws and codes before buying anything.
Shouting “but muh fr33dom!!!” won't do much when the local govt levies fines or seizes your property.