I'm also looking for a way to view all the tables I have in the database; rather than just looking at the tables that relate to that file.
While it's possible to do otherwise, in most cases, all the tables in the file and all the tables in the database are one and the same.
You may find that this link his a helpful starting point, though there are parts that you can probably just skim given your background: https://itunes.apple.com/us/book/filemaker-training-series/id787527886?mt=11
The big thing to keep in mind is that FileMaker is NOT a SQL driven database system. With your background, you'll find yourself reaching for a familiar SQL based tool for working with the database only to find that FileMaker uses a completely different method to produce the same result.
And while FileMaker 12 and 13 do offer a function that uses SQL queries: ExecuteSQL, you'll find that it can only be used in very limited circumstances compared to what you are used to doing with SQL.