Can I improve a downloaded AI model?

I’ve setup llama.cpp engine on my machine, and downloaded a GGUF file. The AI works and, despite being rather slow on my hardware, is still quite impressive.

Yet, I’d like for it to continue evolving — such as by browsing the Internet and/or reading my own files — and it says, it cannot:

Is this really true? How would I go about updating/improving a downloaded model?