Your home page won't come up correctly if you've renamed your home page without updating the Site Information page. When this happens your home page URL (this page's website address) and the field under Site Information where you tell the site what the homepage is, haven't been updated.
To correct this, click Home in your navigation menu, then click Edit. Go to the bottom of the screen and copy the text in the field "URL path settings." The is the URL of your home page (change it now and copy it if you don't like it). Then click on Site Information in your Admin Menu and paste the URL you copied into the "Default front page" field.