I want to change base url and license number.
You can get a new licence for a different number of users in your my.atlassian account.
To change the base url, first make the new url available on your network, and then change JIRA's configuration in "general settings" to match the new url
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
I can't enter to general settings, could you attach screenshots?
Log in as an admin, click the admin cog at the top right, select system. If you don't have "system" on the list, then you don't have the admin rights you need.
Here is a screen shot for the Base URL:
Here is one for the License: