If you are new to crypto trading, and looking for a platform to trade, here are some platforms I use.
Share with all of you~~
Criteria:- Volume
- Secure level
- Liquidity
- Commission fee
- Listing coins
Options:1.
Binance: Strongly and Most recommended! stable, High Vol, safe, liquidity, commission fee cheap, user friendly (apps & web)

2.
Bitfinex: Stable, not many coins available
(ps. Required for 10k deposit)Here is some Korea Exchanges, selling price relatively higher, recommend to sell them here.3.
Bithumb: High Vol, Not highly secure
(ps:security issue happened, consider well if you really want to use!!)4.
Upbit : Not much volume as Bithumb but no problems so far
*******Additional information************
5.
Bittrex - Recommended by
FlamingFingers: High Vol, No security issue ever, simple to use
6.
Poloniex - Recommended by
Reid: Long history, safe, speedy, Lower withdrawal fees(50k sats)
- Not recommended by
elewton: laggy, needs KYC every time
7.
Kucoin - Recommended by
Miro22 and
CodyAlfaridzi: Relatively new and small, but doing well on user experience
8.
Bitmex - Recommended by
CodyAlfaridzi: provide leverage, margin service, high vol, No need KYC.
FAQ:Why do we need to use several platforms? For stable and profitable work in the future, any trader will need several exchanges for several reasons:
1. There are different trading pairs on different exchanges.
2. On some exchanges there is direct input of fiat (sometimes it is very important and convenient).
3. Sometimes all exchanges conduct technical work. Using several exchanges, you will be able to trade even if some of them will conduct technical work.
4. Sometimes exchanges are exposed to hacker attacks. Therefore, you need several exchanges, this will give you the opportunity to always have access to at least part of your deposit.
5. Different exchange rates. Sometimes the exchange rate of a particular currency is very different from the exchange rate on another exchange, so you can profitably sell and buy the currency back.
Thanks EXtremeAEX for information
Welcome to other suggestion 
I really like the way you put up this topic, newbies should really know what exchanger to use and stop making the mistakes of running into fake exchangers that zoom off with their money at last. The exchangers listed here are old and reliable, except Kucoin which is still new but still recommended by many.
Another thing newbies need to know is that they shouldnt only store their coins on exchangers, they should have their own wallets where they store majority of their coins, exchangers can get hacked.