How to get started today

Amit,

When looking to move your existing apps forward to MSIX, I'd recommend starting with the tooling vendor creating your packages today (if you have one). For example, if you're using the WiX Toolset to create your installation packages, we at FireGiant have created an extension to create .appx packages (and soon MSIX packages when Windows provides full support for MSIX) along with your .msi packages. I expect all the other major packaging vendors will support MSIX as well. If you don't have a vendor already, there are several to choose from (I think this presentation showed them: https://developer.microsoft.com/en-us/events/build/content/msix-inside-and-out-pptx).

As to your second question, MSIX will allow you deploy directly via SCCM. You can use the Windows Store for Business but it is not a requirement. MSIX deployment is much more like MSI in that way.

Hope that helps.