New Bitcoin users are not expected to jump into Bitcoin trading too fast. As someone new to Bitcoin if trading is the goal there should be period of learning before venturing into trading, the trick about using different exchanges to trade has been responded by users, you are free to test run many trading exchange in other to find the one you are compatible with, it's not a must to use many for trading.
I agree with you that newbies should first avoid trading. They should not be deceived by what certain people are saying online, claiming they are making profits often from trading. It's not true. Many of them are influencers, and they are doing that just because they want you to join their online classes or buy their signals. But even if you buy the signals, you could still lose money because it's all a way of scamming people.
Newbies first aim should be learning and understanding how to invest in Bitcoin, which carries less risk. Even if newbies are passionate about trading, they should calm down and first learn properly before getting involved in trading. Trading is very risky, and it’s really hard to make profits from it. Even those with proper knowledge about trading lose from time to time.As you’ve also said before, for newbies to calm down and not rush to use any exchange they come across, they should be able to do proper research first before choosing an exchange.