in my opinion for beginners what you should be able to avoid is not to be influenced by market conditions and you have to be careful when you want to buy coins, understand the color indication of the exchange, when green means it's the right time to sell not to buy, when it's red or collapsed then it's the right time to buy, sometimes beginners are still influenced to buy when it's green.
I agree, also they should choose an exchange where they can trade comfortably or has a good credibility. I settle for exchanges that has a decent number of trading volume like with these pairs in case you're curious about the real numbers:
https://trade.kucoin.com/BTC-USDT
https://trade.kucoin.com/ETH-BTC
I don't get influenced by others opinion though, I use what works for me instead of just taking everyone's opinion. Beginners should learn how to see the industry in their own perspective, not based on what the others say about it. It's over when you buy high and sell low
