>>1296145>>1296013>>1296136Plenty of resources online and on Youtube. There are apps like Campermate that show good places to park along with relevant information (if there are any toilets, showers or w/e nearby, local laws etc).
In America/Canada Walmart lets people stay for 1-3 nights and have an RV section in a far corner. For other countries it'll depend on where you are, but "most" will have some sort of equivalent to Walmart that'll let you park for a night.
Like someone said, random streets work too but you just gotta know the area and research beforehand if you can.
Residential streets aren't a good idea because locals are suspicious of strange vehicles, especially an unmarked white van parked on their street. If you park in a neighborhood street I reckon pull up late at night and try to park like say between 2 houses or near a small apartment block. Also don't be a cunt and block someone's drive-way. Just make sure you're up and gone at the crack of dawn though.
Industrial areas can be surprisingly good depending on the town/city. A white service van blends in perfectly there and the area will be dead quiet at night. Again just be gone first thing in the morning.
Busy areas will be safer, because the more people that can see you = the less people will fuck with you. That usually has the drawback of it being noisy from traffic or drunk people walking down the street.
You can always try Couchsurf as well.
For rural might be harder, farmers and countryfolk can be paranoid as fuck about anyone they don't personally know and I can imagine it being more-so for a couple of yuppies pulling up in a white van or a kombi. Best bet is to probably find a remote logging road, bush track or somewhere near a park or forest and pull up there.
There are literally dozens and dozens of "Where can I park?" guides on Youtube though, for various countries. Just watch some.