Antonio:

If you are not an experienced database developer than you should consider reading a primer on database systems.  One such book I found on Amazon for you is at the following link...

the Firebird Database Engine is an excellent engine to work with but rather difficult for even experienced database developers such as myself to understand due to its many differences between it and the more popular engines available.  However, once learned, it is just as powerful as any other engine. 

Please also consider reading my article on these differences at the following link...

This paper highlights these differences in Firebird and provides solutions to comparable solutions so even experienced developers new to Firebird can easily begin to work comfortably with this incredible database engine.

Finally, you should keep a copy of the Firebird Language 2.5 Reference at your side while working with this engine.

If you need a decent Database Manager to help you along, a lot of developers have been recently recommending the DBeaver Community Edition, which supports a variety of database engines as well as Firebird and can be found at the following link...

Steve Naidamast

Sr. Software Engineer