The AppxManifest.xml should be generated as part of the build. The earlier errors you’re hitting are preventing this from happening. If we can get those fixed, the makepri error should go away.
From the looks of things you may have entered ‘Test’ as your ‘Company Distinguished Name’? If so, that’s part of your problem - that field should be in the X509 format, e.g. CN=Test. Also make sure that the subject name for your certificate matches this name. There are a coupleof posts earlier in the thread which might help. Though it’s worth noting that since those were written we’ve tried to improve default behavior, so if you’re just trying to run some tests the best option is frequently just to leave everything blank allowing the build process fill in defaults that ought to work.
I’d also suggest not creating a packaged build when you first start out. You’ll get faster iteration times (packing and signing are skipped) and you don’t have to worry about getting a certificate set up. Best way to do this is just to run through the Project Launcher (or Visual Studio if you prefer), rather than via Package Project.
Service Config and Title Id are part of wiring your title up for Xbox Live. When getting started with UWP and not using Live you should leave these blank. Once you’ve configured your title for Xbox Live on Windows Dev Center you’ll be able to input proper values (note Service Config ID is listed as SCID on Dev Center I believe). You’ll also need to add the OnlineSubsystemLive plugin to your project, and run the GetXboxLiveSDK script to install the SDK in the appropriate location. I should note that the current SDK integration is primarily intended for titles in the ID@Xbox program; as of right now it may require some customization to work with the Xbox Live Creators Program.
Once the Live plugin is enabled the interface is the same as other UE OnlineSubsystem implementations. So if your game works on other online services using UE’s standard interface you should have a great start on Live features.