How to login only to Google Music and not the other Google services? I have Google Music All Access and I have an old unused Huawei Honor floating around. I want to set it up as a Google Music playing device for the kitchen.

I am wondering now: How do I login only for Google Music?

I want to allow guests access to the device in a sort of kiosk mode, but I would not like them having access to my mails and other private data.
As someone who tried to keep a select few Google apps from opening a bevy of other Google apps, just to preserve battery life, and that failed so spectacularly that I opted to use non-Google apps, I have a suspicion you really can't do it unless GMusic runs in kiosk mode (possible; I use iPods for kiosk music so I'm not sure about GMusic).

If GMusic doesn't have a kiosk mode, maybe you can run GMusic in a kiosk browser like SureFox? (I think you can, but it's been a while since I've tried GMusic). There are several of those to try.

But I imagine your best bet is seeing if one of the paid kiosk apps works well with your phone. Note that some of those apps reportedly "mess up" certain phones/tablets, so check the reviews on Playstore for your particular device before trying/buying one.