How they invest in it and get profit.
Before you see them invest they first learn about bitcoin and understand it, they take their time making findings online using different materials and sources to aid their learning and most importantly they have also learnt how to trade and hodl bitcoin investment over time and dont waste time hunting around for other cryptocurrencies.
Is it possible for someone to work and be paid with bitcoins.
Yes, you can earn bitcoin and be paid by rendition of services, creation of values or even mining it
Does Bitcoin work all over the world
Yes, it's a global decentralized digital currency.
I really want to be part of it I would like to invest in crypto and Bitcoin.
Start with bitcoin first before trying out others to avoid complications