I would recommend reading basics of trading first.
Exchange platforms I am using without a problem and can recommend are:
1.Binance.com
2.Bitfinex.com
3.Poloniex.com
3.Kucoin.com
If you want to buy Crypro with Fiat I suggest:
1.Cex.io
2.Kraken
For tracking prices, the best site is coinmarketcap.com
Good mobile apps for portfolio management: Delta and blockfolio.
This is a helpful list. I have been using binance all along. And for a peep in the market I often use coin market cap. I would try out other sites and see how it goes
In coinmarketcap you can see all the exchanges for your coins and pick the best coin where the coin trading for high price.I also suggest Binance for the crypto trading because it looks best when comparing other sites and for the newbies it is perfect.But they need to learn don't keep trading as their full time profession until they keep earning constantly in this field.But OP pick the coin first and then choose the exchange,and also compare some other sites with CMC because there was an issue that they were manipulating the prices.