I joined before knowing my business name -- I still don't know my business name, but still want to plan using Jira. Once I know my name I want to change the URL. I am still in my 7 day free trial. Is this possible? Thank you.
You can raise a request with Atlassian support ( https://support.atlassian.com/contact ) and they will change the url to another <something>.atlassian.net for you.
Obviously, they won't do it many times, so make a good choice when choosing your new <something>. They are working on providing urls that do not have to end atlassian.net as well, but I have no timescale for that.