Passwords are the unsung heros of security. You have to have one and if it is weak you are in trouble.
Passwords can easily be cracked if you use a short one, less than eight characters, and then your bank account is empty. It is very important that you make your password long and include numbers, caps, and special charcters. A pass phrase is even better. For example, Thegr33nGr@ssofWyoM1ng, (ThegreenGrassofWyoMing) is a very strong passphrase. The very best password is very long and totaly random. It would take hundreds of years to crack.
To keep your information secret you should change the passwords often but at irregular intervals. It should be long, ten or more characters with caps and numbers at least. Don’t use the same password for everything, have several, use them in different places. Make them long and have numbers, letters with caps and punctuation. If you have trouble making a random password then go to grc.com and use the random password generator. You can also get an excelent podcast on security at grc.com called Security Now. Hosted by Leo Laporte and Steve Gibson.