The only valid characters for a domain name are letters, numbers and a hyphen “-“. Other special characters like the underscore “_” or an exclamation mark “!” are NOT permitted.
For example: your name.com is incorrect because no spaces are allowed and your-name.com is correct.
A domain name can be up to 67 characters long, including the 4 characters used to identify the Top Level Domain (.net, .com or .org). Do not type the “www.” before your domain name when registering