By default, root is not allowed to log in to the graphical interface. Refer to the following method: ubunturoot is disabled by default, and roo [Detailed]
The mobile phone with Snapdragon 660 processor is currently in the mainstream range, so you can start if you feel enough.
If no one answers this question, they will have the opportunity to be accepted and rewarded accordingly. Let me answer
ZOL certification Red Hat
First level certification
Same brand, same package description
100% favorable rating