If you just issue lp then you should get no response because the commans lp needs parameters, however, I am amazed that someone in the newbies group is turning up without lp even installed.
Anyway, if you install cups you will get lp as it is a requirement of cups.
This should work with
yum install cups
however, as you have RHEL, you may have a license issue when you try to access the default yum repositories. If this is the case and you have no RHEL license I suggest you swap over to Centos.