stepic: 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 Debian possible default full paths are:

/usr/bin/stepic - from package: python-stepic

You may install the required package with command apt-get install {package}

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