what does it mean ?
[ERROR] the variables argument needs at least the strings ^USER^ or ^PASS^: (null)
im trying to

No idea.

What OS are you running?
What program are you running?
What version?
What are you typing to get this error?
Is it a script?
Is it programming code?
Can you share the code or script?

What you just said is akin to saying "I have a problem with my car, please advise how to fix." See here on how to ask good technical questions: http://www.catb.org/~esr/faqs/smart-questions.html

1 members found this post helpful.

ahh damn its not answerable :S
im trying to learn how to perform pen tests
according to LQ rules i can't say what im doing exactly, which programs im using etc..
however you've answered me here
i had a problem with the car ( software )
i focused on the software and found the problem. thanks a lot.

You can certainly find help. Most utilities have a website/forum/IRC channel/community associated with them that you can visit. There are also plenty of pentesting guides out there, how-to's, various information regarding it, you just have to look hard enough. BlackArch has a community https://blackarch.org/community.html, as does Kali linux, https://www.kali.org/community/, and both are very geared towards the pentesting and security community.

I would suggest studying the basics of Linux, Windows and Networking before you go any further though. Understand that Pentesting can be of two types: A) Script kiddies that run utilities and have no idea what they are doing B) Pentesters that use tools to prod systems that they understand to find gaps and vulnerabilities. If you are hoping to do this professionally you will want to be in the second group.

Thread has been closed due to the topic being deemed inappropriate for the site, per the rules of LQ.