Itunes12.6.1.25 / Windows /

I have question, i read that there is no Appstore on the new version of Itunes, why and how to buy apps then,

Im not planing to update it and my question is how Device restore will work on older Itunes when the iphone or Ipad needs pull on the latest IOS, will it denied to restore it or it will download the latest for older Itunes ( 10.3.3 for example )