hi am newbie here..can anyone suggest me good exchange to stat buying cryptocurrencies..
Welcome to the cryptocommunity, mate!
There are different exchanges based on different features and prices and it depends that what are you interested to buy.
If you want to buy Bitcoins, try Localbitcoins, Coinbase, Kraken, Bitstamp and/or Bitfinex.
And for altcoins, Bittrex and Poloniex hold the most volume and Liqui, as well as Binance are also fine based on your convenience.