I need your help (linux man)

install ubuntu but I face some issue with it
1- I cant access by root username
2- I don't Know what is the root password

That's because the root account is disabled by default (by having no password)
Login using the username you selected at setup and type in
[code:1]sudo passwd root[/code:1]
Then type in your new root password.

thank you very mach

Do you need the root account in Ubuntu? Because I use the sudo command and simply use the password I used when I setup my normal user account.

skep u need root in ubuntu cos there are some certain features u will need access and u have to have an administrative right above the one u are using presently... that happens only in root.