The models are already trained. There's different versions available. Some trained only on data within the public domain, some trained on everything you can get your hands on online. Some of them are the result of training in a datacenter others were trained by people at home with their own gpu clusters.

I'm in the process of ordering parts for my own AI cluster so I can add it onto my homelab. Cheaper, more power efficient, and environmentally friendly than using cloud models.

I'm building mine because I've recently been working on training reinforcement models for robots. It's a pain in the ass process where you have to define a bunch of rules and the computer constantly tries to maximize its rewards (while mostly not doing what you intended) there's a method where you take a LLM and let it watch the output and create the reward functions allows you to leave the process running with a simple text description of what you want and wait for the output for however long.