While we cannot offer you specific certification or career advice, we can tell you that the realm of information security is quite vast and you therefore need to determine what you like best before committing yourself. In general, only knowledge and experience are required in order to offer your services as a pentester; however, certifications do help in building your clientele. All of our courses focus on offensive security, most specifically, the field of penetration testing.
Our Penetration Testing with Kali-Linux (PEN-200) course focuses on modern techniques used by penetration testers all across the globe, so it would be a great start for those new to the field.
Our Advanced Web Attacks and Exploitation (WEB-300) course focuses on increasing your understanding of the art of exploiting front-facing web applications. AWAE is for experienced penetration testers looking to take their web application testing skills to the next level and for web application developers who need to understand how their code is attacked.
In addition to PWK and AWAE, we also have a course entirely devoted to wireless penetration testing, OffSec Wireless Attacks (PEN-210).