How can I access my iCloud?

Sounds like you might need account recovery - Two-factor authentication for Apple ID - Apple Support.

"If I can't sign in, how do I regain access to my account?

If you can’t sign in, access a trusted device, reset your password, or receive verification codes, you can request account recovery to regain access to your account."

Can you be more specific as to how you're trying to manage your iCloud account as this is a very broad subject.