Coming from using Xcode 13 to 15, I'm missing the new concepts on how to commit and push code changes to GitHub in 15. I tried using the menu Commit... (like I did before), wrote a message, and pushed the changes to my repository. Now when I try that, a new window appears with things about, staging, append, etc, and I'm not sure what all that means. Is there (and where is it) documentation on this new source control paradigm? All I find is docs for the "old way".

After Xcode 15 update, to update my older iOS apps, Xcode says I must install the iOS 17.0 something. When I choose to install, the iOS 17.0.1 Simulator (21A342) downloads completely (~7gb) but even after 10-15 minutes the dialog Verifying "iOS 17.0.simruntime"... never progresses even once. I am unable to do anything with Xcode Because of this I am unable to build my updated iOS apps because it keeps cycles in this same loop with the same results, now 2 or 3 times. Does this verify take hours? How can I get this to verify and get back to updating/building my iOS apps?