bash can not find sudo command

soroosh
I'm trying to work with this friendlyarm 9 board I got recently but it
can't find some basic bash commands and I couldn't find a solution for it
anywhere. When I type any command with sudo or even when I type sudo alone
I get

/bin/sh: sudo: not found

It is the same when I type bash:

/bin/sh: bash: not found

Should I add something to its PATH? or anything like that?