I am preparing for a QA job that requires networking skills

I applied for a QA job that requires both Linux and Networking skills. I don't yet have the skills, but I am planning to learn and practice. Perhaps on a future interview I would be prepared. They only considered me because I already work in the same company and they want me to get an idea of what is going on there.

I passed the interview and they scheduled a practical interview for me where they would give me a Linux application that I would need to debug and make it work.

It would require editing text files, check TCP handshakes,SSL negociation,(netcat,tcpdump,wireshark,curl,netstat,ss,htop)

Any advice on how can I make a practical project that would walk me through the required skills?

Any application/server I can install on a Linux VM and attempt to troubleshoot?

Any advice is much appreciated.