Run an open source one. Training requires lots of knowledge and even more hardware resources/time. Fine tuned models are available for free online, there is not much use in training it yourself.

Options are

https://github.com/oobabooga/text-generation-webui

https://github.com/Mozilla-Ocho/llamafile

https://github.com/ggerganov/llama.cpp

I recommend llavafiles, as this is the easiest option to run. The GitHub has all the stuff you need in the “quick start” section.

Though the default is a bit restricted on windows. Since the llavafiles are bundling the LLM weights with the executable and Windows has a 4GB limit on executables you’re restricted to very small models. Workarounds are available though!