How can I start to create, delete, etc., a table in Fedora 13? How can I initiate to create a basic table in Linux, what are the commands? Will I have to install firstly a database like ORACLE in my Fedora environment or is it already installed?
Operating Systems typically don't come with database server software pre-installed because each one meets different needs/requirements. The vast majority of database servers use SQL, and there is a wide range of choices both in commercial (e.g., Oracle, DB2, etc.) and free (e.g., open source, freeware, etc.) offerings.
For my projects, I find that PostgreSQL is an excellent SQL server that more than meets my needs, without wasting resources. It's free, and open source, and is fairly straight-forward to install in Linux and many other Operating Systems. I suggest you start with PostgreSQL if you don't have something else in mind:
Your first step will be to install a database engine (whichever one you choose, which may or may not be PostgreSQL depending on what meets your needs), then learn how to use its administration tools. The most basic tool is the "SQL command-line utility" which seems to be named differently by each project/vendor.
Once you learn the basics of the administration tools, you'll be able to create your tables (which will also require at least a basic understanding of the different data types so that you can design your database in a manner that will be useful to you).
The command you'll need to use, for which you'll want to refer to the documentation for the database you choose to use, is: CREATE TABLE
There are a variety of parameters, such as the name of the table, column [data] types, various constraints, and many other things. The documentation can be found here: http://www.postgresql.org/docs/9.0/interactive/sql-createtable.html