MySQL newbie question

I just started learning MySQL a little and i have a little question.

Is it true that for my own website 1 database is enough?

Just for everything like a guestbook and a shoutbox etc. i have to make another table? Is that correct or am i tottally wrong?

Another one my server haves MySQL and thats the way i want to work now
While learning i downloaded a flash guestbook for mySQL and the PHP script starts with:

$DBhost = “localhost”; // Database Server
$DBuser = “root”; // Database User
$DBpass = “”; // Database Pass
$DBName = “turorials”; // Database Name
$table = “guestbook”; // Database Table

what do i have to fill in if i have an external mySQL browser? The name of my website which is combined with my MySQL database?

Thank you

Jos Koomen
Hoorn, The Netherlands