Without knowing anything about your specific setup I’d guess the issue is with docker not playing nice with your OS or vice versa. Can you execute the standard docker hello-world app? https://docker-handbook.farhan.dev/en/hello-world-in-docker/
If not then my money’s on this being an issue the OS. How did you install docker on mint, using sudo with a package install?
Fyi don’t feel bad - I installed docker on 3 different Linux distros last month and each had their quirks that I had to work my way through. Docker virtualization is some crafty kernel-level magic which can go wrong very fast if the environment is not just right.
The easiest way to run local LLMs on older hardware is Llamafile https://github.com/Mozilla-Ocho/llamafile
For non-nvidia GPUs, webgpu is the way to go https://github.com/abi/secret-llama