I just want to know how those people behind bitcoin secure the money they will invest because as far as I know there are lots of hackers all over the world.
If you're doubt about the software, website, exchange that allow you to put your bitcoin then you can try Hardware wallet which is offline storage, but if you want looking for another alternative besides Hardware wallet you can try to download software wallet that I recommend you Electrum. There's really so much hackers recently and it will still remains that's why careful when you're using internet.