I meet lots of problems when i installed and use ubuntu 16.04.below is my using note:

(my operating system is english, so i use english and let this as an exerices.: )

1. First probelm :   su: Authentication failure

Open Terminal Window and input command of su,then input the pass, but is return an error : su:Authentication failure.

the resolution is input command:sudo passwd root and input the new pass.then ur can resolve it.

2. Update the system:

　use command :  apt-get update  then　apt-get upgrade
It maybe useing half an hour to get info and soft from internet.

3.To be Continuing

Ubuntu16.04 Useing Note