1000USD is a big money to buy only a single cryptocurrency. Better consider investing also on both Crypto market and Forex market. Cryptos, especially Bitcoin, are volatile. Having you huge money be invested on it alone would be too risky. But if you would really wanted to buy 1Bitcoin, there are a lot of marketplace to buy near your place (in which mine has too many). But still, you cannot buy at a low price now. You must either wait for another decrease or invest just atleast half of your money.
In how to buy, there's a lot of wallet that offers such feature. Never ever do it on an exchange unless you wanted to enter the world of trading. But if you do so, better study first the world of crypto market and have training in online trading simulations.