Never invest more than you are willing or able to lose, Bitcoin is a very risky investment and you should keep in that in mind at all times. After buying Bitcoins make sure to move them into your own personal wallet and never leave them at the exchange. My personal recommendation is to use a hardware wallet to store your Bitcoins. If you cant afford a hardware wallet, try a paper wallet. Make sure to buy Bitcoins only from exchanges that have proven their reputation. Buy Bitcoins through Dollar cost averaging, this means that you dont buy all of your Bitcoins in one trade but instead buy a fixed amount every month, week or even day throughout the year. These are my personal idea.