Almost there ... plz help

I need to get PostFix started but it wont because my config is not correct

this is what i have now

/etc/aliases

mailer-daemon: postmaster
postmaster: root
nobody: root
hostmaster: root
usenet: root
news: root
webmaster: root
www: root
ftp: root
abuse: root
noc: root
security: root
clamav: root

that was all default , what should i change if anything and chnage to what exactly /??

thanks in advance

okay fixed it myself , still got more errors but getting even closer to having finally a virtual domain

here is how i fixed the above

Something went wront with installation. Edit your /etc/postfix/main.cf manually and change myhostname = to right one. … (which should be "root")

here is an error i get when trying to update

postfix: warning: valid_hostname: invalid character 123(decimal): {MTA_HOSTNAME}
postfix: fatal: file /etc/postfix/main.cf: parameter myhostname: bad parameter value: {MTA_HOSTNAME}

here is an error i get when trying to update

postfix: warning: valid_hostname: invalid character 123(decimal): {MTA_HOSTNAME}
postfix: fatal: file /etc/postfix/main.cf: parameter myhostname: bad parameter value: {MTA_HOSTNAME}