Camping

Camping is illegal in some municipalities  Make sure to check with the local authorities for laws in your area. My suggestion is don't mess around with a tent. Sometimes spanging for a motel room is not a bad idea. The best places to "camp" depends on what weather is happening.  

Warm Weather clear skies

If the weather is fantastic you might want to find yourself a grassy field to lay your tarp on. But if you are in the urban jungle go to a park there's bushes and benches. Some places make it illegal to cover up with a blanket. Some buildings have ladders on and you could hypothetically get on a rooftop and sleep there.