WordPress has clear documentation on how to use it's friendly user admin. Here is how WordPress explains how to Add A Page:
- Login to your WordPress admin (usually you can get to your admin by going to: www.mydomain.com/wp-admin).
- Navigate to Pages > Add New
- Fill in the fields: enter your post title in the upper field, and enter your post body content in the main field.
- If applicable, select a template, and add a featured image.
- Once the fields are filled out to add your finished post to your website click on 'Publish'.
For full WordPress details on how to use templates and add subpages plus other Pages options Click Here.