[Pinguinn]

You might want to start learning SQL first.
After that, you can start focusing on the functions.
The functions you probably going to need the most are:

• mysql_connect
• mysql_query
• mysql_store_result
• mysql_free_result
• mysql_real_escape_string
• mysql_fetch_row_format
• mysql_fetch_field_row

All functions: click here
This can help you as well
And this as well