I’m only a consumer of GPT. Any pointers as to where someone like me with software engineering experience but literally no AI knowledge can train my own GPT on

I’m only a consumer of GPT. Any pointers as to where someone like me with software engineering experience but literally no AI knowledge can train my own GPT on my own data sets? In my case I have downloaded some public domain databases (1-7gb each) and I would like to get some additional insights out of them. I have been querying them and using them to build my company but I’m curious to know if GPT can help me in that regard.