There are 2 options to create an account in Echo network:
In the first case, you will use the RPC API of the node running by someone, who provided the opportunity to register accounts through it. To register through a public registrar, you must use the appropriate api method. Details of the request you can find here - https://dev.echo.org/developers/apis/registration-api/.
Also, if you already have an account, you can register a new account yourself by sending an account creation operation to the blockchain. https://dev.echo.org/developers/operations/account_management/_account_create_operation/
You can also use the desktop wallet. For example, Blip Wallet allows you to use both registry options.
A valid name consists of a dot-separated sequence of one or more labels consisting of the following rules:
In addition, we require the following:
ECHO_MIN_ACCOUNT_NAME_LENGTH(now = 1) and
ECHO_MAX_ACCOUNT_NAME_LENGTH(now = 63)