If you choose to log in with your email address and password, you will have to fill this information every time you log in, unless your save your credentials on your computer.
You can :
change your password from your Avatar > My profile > password.
Change your email address from your Avatar > My profile > Email address. If your company only allows you to enter business addresses ending with the usual company addresses, it is not possible to enter a home address.
Reset your password from the Login page, in the right of the "password" field, by clicking on "Forgot?".
It is not possible to log in via Google or another way for now when you usually log in via an email address.