I have not yet met anybody who managed to get Joomla up and running as they wanted it satisfactorily as a "beginner", and even many "profis" avoid it.
Yes, you can do "everything" with it (not true by the way!), but it might take you a week to do something simple.
If you want something which works out of the box, and has good understandable documentation and a lot of options, then try this;
http://www.cmsmadesimple.org/
also a learning curve involved, but a lot less time and effort involved than with Joomla.
You can also learn a great deal using this;
http://wikkawiki.org/HomePage
I would also advise you to use
http://www.wampserver.com/en/
instead of xammp.
The database tables have nothing to do with the templates, except that systems using SQL databases and similar will of course store the data there.
Templates, and appearance are usually manipulated using CSS ( Cascading Style Sheets)
( Get free lessons here;
http://www.html.net/tutorials/css/lesson1.asp ) but use defaults or "ready made" templates first, as this is one of the most difficult areas for a beginner.
Normally, the user/administrator of a dynamic CMS or similar system does not need to create any tables, the software does that, given the installation parameters. Any further tables required are also generated automatically. You merely have to ensure that your main server ( where the actual program files are) can communicate with the SQL server ( where the data is stored, often on the same physical machine).
You only need a single database to run a site. Having ten is no advantage. Depending on what you want to do, other parameters are of much greater importance. I think you are confusing a database ( a collection of tables) with a data table.
As for not being able to "beat the price", also not true;
http://www.bplaced.net/
just one of the reliable free hosters I recommend to various people. Also with instructions for installing various stuff. You need to look around the site. This is a German site but they also have an English forum with good support from other users. You might be better served with a free host in your own country.
Most CMS and similar systems will run on the Wampserver ( on your local machine ), given above.
"Localhost" is often the name of the server, but it can have other names, it DOES NOT mean a local computer. ( although it can if the webserver is on your local computer). Many webservers use the default name "Localhost", others dont. This is often a point of considerable confusion for beginners.