SpatiaLite is an SQLite database engine with spatial functions added.
This Quick Start describes how to open a database with the command line and the GUI application.
Open a console and open a sample database with spatialite:
spatialite /home/user/data/spatialite/regions.sqlite
select r.NOME_REG, a.Nome from Aeroporti a, reg2008_s r where CONTAINS( r.Geometry, a.Geometry ) order by r.NOME_REG;
You should see a set of Airports in Italy
Here are some additional challenges for you to try:
To learn more about SpatiaLite, a starting point is the Documentation and tutorials page.