@Lermatroid you didn't provide any information to help. No idea even which version of the OS you're running.
Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first
if you have no cec package, your OS is likely too old. you can install without it with some hackery but if your os is old, you probably want to upgrade.