I'm trying to create 2 brochures in one 8.5x11 paper - IMAGE example included..

You will need 8 pages setup in a spread of 4 pages.

It's 11inches wide - so 11/4 is 2.75 inches per page. 

You can actually type 11/4 into the measurements
I've kept the margins as the default - that's up to you - you should keep all text within the margins. 

And if you need any colour or images to go right to the edge of the page you will need to Bleed them off the side into the artboard - called the Bleed area (you can look that up)

This is the bleed setting

Go to Window>Pages and  you will see the Pages Panel

Should look something like the above

Select all the pages in the Pages panel

Right click and choose to turn off the selection of allow document pages to shuffle (no tick beside it)

Select pages 2-3 and move them beside page 1

And do the same with pages 6,7,8 and move them beside Page 5

Your document now looks like this

5-8 are the inside pages (bottom) - which are actually Pages 2,3,4,5
Page 1 is the top right

Get some paper fold it up like that and write your page numbers on them.

Then follow it. 

Hi @Christopher32487628href:

These two are available to license using stock.adobe.com.

https://stock.adobe.com/Search?ff_4815162342=true&k=four%20fold%20brochure&locale=en_US&x-product=IDSN%2F18.4&x-product-location=CCXStart-fnft%2Fundefined&x-radarSession=undefined&x-appSession=1C21966C-4D7B-4866-BA45-BAA4F86B6047&ute=true&filters%5Bcontent_type:template%5D=1&filters%5Btemplate_type_id%5D%5B%5D=3&as_channel=adobe_apps&as_source=app&as_campclass=brand&as_campaign=templates_IDSN

You can also create one on your own by dividing an 8.5" x 11" page into four columns. 

In either case, to see the front and back at the same time, right click page 1 in the Pages panel and start page numbering at  2 in Numbering & Section Options. 

~Barb