Answer 1

Uhh... As much as I know... they can't help you in making the skeleton or body of an application...

For PHP : https://code.tutsplus.com/tutorials/15-wonderfully-creative-uses-for-php--net-4714

For SQL : SQL can be used to share and manage data, particularly data that is found in relational database management systems, which include data organized into tables. ... Using SQL, you can query, update, and reorganize data, as well as create and modify the schema (structure) of a database system and control access to its data.(Google)