No, content items cannot be assigned to multiple categories or sections.
Newsflash is a module that displays content from specific sections and/or categories.
► In the administrative back end from the top menu select “Modules => Site Modules”.
► Click on “Newsflash” to edit the module.
► Go to the parameters section of the page.
► Next to the “Category” parameter click on the drop down menu to select which category of content items will be displayed by this module. (In older versions of Joomla! You need to manually enter the section and/or category id numbers).
► Click the save button to make your changes permanent.
The simple answer is that you get the URL for the page you want to link to. Then you make a link using whatever editor you are using or with html if you have nowysiwyg.
The more complicated answer is that some editors have fancier links managers. For example with the JCE editor you can add the advanced linking plugin and it will give you nice lists of static and other content types to pick from.
Frontpage is a component that is part of the core of Joomla!, like the front page of a newspaper, it shows (usually) multiple pieces of content arranged in some way.
When you install Joomla! the front page component is by default set as the homepage of your site (that is it is the first link on your Main Menu) but front page does not have to be your "home" page.
What exactly appears on the front page and how it is laid out is controlled in two ways. First, if you open the menu link in your menu manager in the backend there are numerous parameters that control the number of items shown, the number of columns etc.
To control which items are shown you must also indicate that an item should be placed on the front page by editing the parameters for the content item. In the backend this will be indicated by a check mark in the front page column of the list of content items.
In addition, you can use the front page manager (in the content menu of the backend) to control the publication dates and other variables for content items that are on the front page.
The basic structure is:
Sections include Categories.
Categories include content items.
The content items are what you would think of as web pages in a traditional html site.
Both section and category "pages" can be created to serve (more or less) as the home pages for the categories and sections, respectively.