Well, first you need to do is to find a wallet, As of the moment, there are many wallets that support Bitcoin. Please read this article to know how to choose a wallet https://bitcointalk.org/index.php?topic=1631151.0,

After you have chosen a wallet, you can now buy bitcoin. Buying bitcoin is really easy, you can either buy it, from exchange, people and some bank also offer this but of course, it really depends on your current location. But the easiest way to buy it is buying them in coinbase.

But of course to tell you honestly, You must be aware of this first if you really wanted to buy Bitcoin, Bitcoin is very volatile, you may lose or gain money in an instant. So before you buy them, please be advise that you can only invest what you afford to lose.