Learn how to use UUIDs in MySQL for your table IDs, rather than using auto_increment.
A couple of examples of using joins or nested queries to select and combine data from multiple tables.
Can MySQL ensure that if a value is in one table, it doesn't exist in the other?
Can you create a foreign key that references a column in another table that itself is a foreign key that references a column in another table?
This tutorial will show you how to install various versions of MySQL server on Debian 9.