Salesforce connect with Java

I tried to start my first program to connect to Salesforce database. I downloaded this project: and created an trial account on Next I reseted my security token.

When I try to connect I get an invalid useraname or password exception. What should I do to fix this ? I am using my email (used to register) and the security token ?

One more question: how is possible from SOQL to list existing tables and columns ? My intention is to write an open source JDBC driver on top of this ( in web I found only commercial drivers). Maybe you know an free one ?