I have a client that would like me to take artwork off the slide show on his home page & format a brochure/folder.
I have attached an example.
The plan is to insert show promotions and business cards into these folders.
Can I use InDesign to create the folder font and back? Or some other Adobe App.
Yes, you can use InDesign.
For the images you will need some with higher resolution than for web.
You might find these online video traing tutorials helpful (you can get free 10-day trials):
And of course you can return to this friendly forum with questions about specific issues.
In this case, the images from the linked page could work; thefy are quite large, and if they are sized to around 1.5 x 3 inch, they come close to being 300 ppi.