When creating a password it's more secure to use a combination of numbers and letters.
There are password generating programs that do just that.
However, it's also more secure to create a password that can be memorised and not written down or kept on your computer.
Many ways of doing this include using a word and a number you can remember, but combining them in a way that you can remember.
Say the word is smith and the number is 1964.
Using those letters and numbers, the password could be s1m9i6t4h, or sm19i64th, or smi1964th, etc.
This is obscure enough so long as your name is not Smith which hackers might start with if they knew.
You can use any character in a password, but not spaces.
To make it even more secure use upper case and lowercase letters, numbers and other characters. e.g. s[1M9i6T4}h.
When using a password that has been emailed to you for say FTP, you can save a lot of frustration by copying it from the email [Crtl C] and pasting it [Ctrl V] into your FTP program which then encrypts the password so that you only see • • • • • • • • .
Frequently, typing a sent password (instead of copying and pasting) can let you mix up say 1's or l's, or O's and 0's.
Keep your life uncomplicated.