Q.   I have created content, but 'Welcome to Drupal...' still displays on my homepage.

In order to remove the existing content on your landing page, you need to 'Promote' a page, event, or product to the front page.  Scroll down to the bottom of your Edit page, listed directly above 'Save,' you will see a section for 'Publishing Options.'  Select 'Promote to Front Page,' and save.