Get some experience using the shell on a daily basis (managing packages, searching files), as Ameed suggest. Then, you can focus on some core concepts:
Users, groups and permissions;
Filesystem hierarchy;
Shells and Shell Scripts (zsh and fish will improve you productivity);
Latter on, you can have some good time with network services (like openssh, openvpn, samba, etc) or even pentest. Switching to Fedora (or Arch) could also be a good challenge. And, at last, you can study about Docker or virtualization.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
Get some experience using the shell on a daily basis (managing packages, searching files), as Ameed suggest. Then, you can focus on some core concepts:
Latter on, you can have some good time with network services (like openssh, openvpn, samba, etc) or even pentest. Switching to Fedora (or Arch) could also be a good challenge. And, at last, you can study about Docker or virtualization.