You can get bitcoin by using sites who sells Bitcoin online like sex.com. But should support to your geographical area to buy using your VISA cards. Localbitcoins.com or trusted local sellers are good options to buy bitcoins. You can offer some of your service like social media promoting to ICO projects & can earn crypto coins. Then exchange in to BTC.

Bitcoin is popular as a investment method with high volatility. You can trade, exchange BTC instead Fiat currency like US dollars. These are basics. when you deal with VISA or any cards there a intermediate & they take a commission or fare to do it & handles by them with limitations & restrictions. In crypto there is no intermediate like that. You can directly transfer to receiver without any intermediate & commission to them. BTC will solve a lot of problems of these busy world by a click from your smart phone. As a method of investment you can buy bitcoin in when in dip & hold for long term to take profit.