Before you invest, you must know that BTC is full of risks, you have to be patient and keep it, I believe the value of BTC will jump and make your investment grow. you can buy it in several exchanges by depositing fiat currency and exchanging it with btc
People do need to understand that btc is highly volatile and involved huge risk. Yes higher the risk even the rewards can be greater. So one should have patience and ready to take risks then only do invest in crypto currency else if you invest and require money then you might get struck if market crashes during that time.
I never suggest you to invest your money in stock markets. They're fake and mostly people lose there money. I have experience with stock exchange and i did invest for long term but i lose my money.