Being social is the key to getting access to such networks. If you are in a public place Yoh can politely ask them. If you are at your home, try to maintain a good relationship with your neighbour and ask them if they are willing to provide you with access.
Never try to hack through a network as it may warn the real owner of the network and it may blacklist. No one likes a thief in their neighbourhood, so don’t try to act on illegal acts.
You might try some common passwords such as house name or family name etc, that people usually prefer.