There are a few ways to earn bitcoin: freelancing for companies which pay in bitcoin, faucets (a good place for beginners to start), etc. but I will like to advice you to be careful, as there are many scams that are going on online, who will offer you fast and easy ways to multiply your BTC. Stay away from these so called programs. These are all ponzi schemes and will rob you of your hard earned money. A rule of thumb to point out ponzi schemes is that, if its too good to be true then is not.