You can use set operations to combine the results of two queries. One such operator is UNION ALL, which gives you results from either of the queries, including duplicates. The UNION operator provides a similar capability. But it removes the duplicate records from the result.
You can send the output of the Oracle SQL*Plus tool to a file. This is done with the SPOOL
I may come back and share additional details from the other 9 chapters of my self study guide. However I just started my instructor led training for my Program with PL/SQL class. I suspect I will be sharing tips from what I learn in person every day. Either way you benefit.