Maybe I'd invest 6000 with no stop loss, 6000 with a stop loss to 25% lower? Then see what happens and buy more if there's a dip. I know it's a shame I woke up too late so I don't need to be reminded of that, but I would really really appreciate if you could share your knowledge of how to salvage whatever can be salvaged, thank you!!
Rather than take advice from us on what would be the best thing to do, why not put up a market test. You will trade with a low amount and see what strategy will work for you. It's not advisable for you at the moment to just fill your bags quickly as you don't have any idea what you are doing.
You have funds to spare and I think you afford to lose it so use that for the moment while gaining knowledge.
I'm not the type of person that will tell anyone to just buy bitcoin. Even saying bitcoin has a future, that is non-sense if you don't know how to manage it. Trade little by little and don't stop until you understand even the basics.