You can create new top-level site collections when you create your Web application or any time later using the Create Site Collections option in Application Management. You can create a top-level site collection using either the root URL of an unextended Web application or a managed path such as /sites or any other wildcard inclusion path you have created.When creating a new site collection, you will provide the following information.
- Title and description
- A quota limit template if required
Make sure to choose the correct Web application before creating the site collection so the collection is available in the correct Web application.
If you have any queries regarding the above mentioned information then please let me know, Thank you