There are many exchanges where you can actually buy bitcoin. But I will not recommend you the exchanges where I have not bought bitcoin or I have not made transactions before. So in my list I have binance which is of course will be the top 1, the next is bitfinex, bittrex and coinbase. There are also many good exchanges out there but these are the ones that I have used and I have not had any slight problems in terms of bitcoin. But if you are in the Philippines I do recommend coins.ph which I usually use.