It is only day 2, but we have already covered how to retrieve fields from multiple tables

SELECT field1, field2 ...
FROM table1
INNER|LEFT|RIGHT JOIN table2
  ON table1.shared_field1 = table2.shared_field1
  AND table1.shared_field2 = table2.shared_field2
  ...
INNER|LEFT|RIGHT JOIN table3
  ON table1.shared_field1 = table3.shared_field1
  AND table1.shared_field2 = table3.shared_field2
  ...

and built-in functions both for strings and numeric values (aggregate).

Download the class notes for day 2.