Well, fix your self first before you go thru,  because in crypto theres a lot of challenges you can encounter. so being a broke man you cannot done any single of activity if you dont fix your self,  any ways about your concern,  use coinbase if you want to own a any single bitcoin to role up into crypto business. $200 is enough for me to role up into trade most probably altcoin to get profits. Then try to visit some other trusted trading sites like etherdelta,  hitbtc,  poloniex,  cryptopia for you to meet the other alts that you can really get some profits from your $200. But choose wisely.