Sorry but for some reason, I can't seem to follow why a Blender file I bought doesn't open up all the textures that come with it. I can see the texture folders extracted and the .blend file. The textures are all .png yet for some reason when I open up the .blend file, the textures don't load completely with the object. Only some show.

Any ideas on what I need to do to help Blender find the texture files?

The only thing I can think of is the blend file was created in earlier version of Blender than the one you are using this tutorial might help since I recall this being an issue when when opening files from version 2.79 and older into the new 2.8 at the time Opening old .blend files (missing images)  I hope this helps 

After you have opened the blend file go to:  File / External Data / Find Missing Files

Navigate to the folder with the textures. 
Once the textures load correctly into your scene resave the file.

Thanks! The Find Missing Files has worked so far.

With your blend file open if you go to:  File / External Data / Pack Resources then Blender will save your textures in the blend file.  It will increase the file size of the blend file but you can move the blend file from computer to  computer without the need of a separate folder with your textures.