I'm not sure what creating mysql databases has to do with DirectAdmin. You might want to check out www.mysql.com and do a search for "create table". It will show you all the proper syntax.
You can also create tables in phpMyAdmin after you create a database. Just go to domain.com/phpMyAdmin
You give the table a name, enter the number of columns (fields) you want to use. Click "go".
For each field, give it a name, specifiy a data type and click save.
You might want to learn a bit more about mysql and its data types if you arn't sure about their settings. There is a documentation button in the "Type" header to: http://www.mysql.com/doc/en/Column_types.html