man1: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/share/man/bin/man1 - from package: filesystem

You may install the required package with command yum install {package}

Error in other languages:
man1: bevel nie gevind nie
man1: comandă negăsită
man1: comando não encontrado
man1: commande introuvable
man1: command not found
man1: käsku ei ole
man1: không tìm thấy lệnh
man1: komanda nerasta
man1: Kommando nicht gefunden.
man1: kommandot finns inte
man1: komut yok
man1: nie znaleziono polecenia
man1: níor aimsíodh an t-ordú
man1: no se encontró la orden
man1: no s'ha trobat l'ordre
man1: opdracht niet gevonden
man1: parancs nem található
man1: perintah tidak ditemukan
man1: príkaz nenájdený
man1: příkaz nenalezen
man1: команда не найдена
man1: командата не е открита
man1: 命令找不到
man1: コマンドが見つかりません