I’m not sure whether it’s a common challenge, but one thing I struggled with was assessing my own work (am I doing it “right”?).
I was the first and only tester in my company for a couple of years, so there was no one to give me any guidance or mentorship - I was completely self-taught. I was also very lucky in finding the testing community very early on. I think this helped me get started on the right path of what quality and testing is really about. Being exposed to practical, modern ideas about software testing was very exciting for me, but I didn’t know whether I was applying those ideas “properly”.
What really helped me to get the feedback and confidence I needed was starting my own blog, as well as participating in online discussions with the community. Although I still didn’t have direct feedback on my work from other testers, I at least had feedback on the ideas and principles that I was working based upon. I’m very grateful to the testing community for welcoming and supporting me so much.