How do I change my password?

#1

How do I change my password?
How do I change my password?
How do I change my password?

I chose an account registered with icloud, and the software did not prompt me for a password when I registered. When I log in with a computer, I need to enter my password, so the computer cannot log in.

I want to delete the user I created before on the iPad, but the system has been unresponsive. After trying several times, the account cannot be deleted.