I use alot of Ubuntu.. and in Ubuntu your first created user always has sudo access.. but in CentOS and in OpenSuse you do not.. so here is how to grant that access..
First in both you log in as yourself and open a terminal.
You then change user to root
Put in your root password when prompted.
Edit the sudoers file
in vi ( I hope you are comfy in vi.. I’ll write another post about it soon I’m sure. ) look for a line that sez
root ALL=(ALL) ALL
and add a line under it just like it that sez
username ALL=(ALL) ALL
(replace username with your user’s name.. of course.. )
save the file. (in vi you press esc and then :wq! )