us-east-2 US East (Ohio) Not required
us-east-1 US East (N. Virginia) Not required
us-west-1 US West (N. California) Not required
us-west-2 US West (Oregon) Not required
As for Credentials, that will be your security/secret key and you can get that from the IAM page from the AWS Console.
You can also use aws-cli or something to rotate you key and get a new one if needed.
To find your region, when you login you generally will be in your default region. Just click the drop down to find it
Was trying to find where the keys can be found via the website but since we moved everything to a SSO we no longer have individual AWS accounts so I cant look that up anymore since my admin login doesnt work that way anymore