I don't completely understand your question, but I'll give it a try. When you want to combine data from more than one table it is called a "join". Most tables should have a unique identifier called a "primary key". This is usually a number. This key can be referenced in another table. In this case it is called a "foreign key".
For example, you could have a table called "EVENTS":
id | title | description | location_id
And a table called "LOCATIONS"
id | city | state
The "location_id" in the EVENTS table is a foreign key referencing the primary key "id" of the LOCATIONS table.
These would be joined like this:
SELECT EVENTS.title, EVENTS.description, LOCATIONS.city, LOCATIONS.state
Using Joomla's setQuery the elements of the MYSQL above would be added in sections.
I don't know Joomla well enough to provide you with the exact code.
Let me know if you have any questions.