I used the wrong url during installation and I am unable to change it via the admin panel. How to do it via phpmyadmin? What table is the site url stored in?
Solved: Answer = mybb_settings.
There is no need to do it in phpMyAdmin. Open the file /inc/settings.php, search for 'bburl' and change the value there. You might also check the cookie settings. Now you should be able to login into your forum and make the same change in ACP > Configuration > Settings > General settings.
Don't edit settings in the database, it's not what the forum actually directly uses. If you edit settings in the database you have to then delete ./inc/settings.php so it regenerates with the new setting you set.