yes, some pretty good suggestions, especially for beginners, at least the suggestions above can minimize investment losses. Besides that, you also need to pay attention to financial management, my advice is not to invest in one coin, if you have a lot of money, prioritize investing in BTC and set aside some for top altcoin investments.
3. You dont want to rely on a single coin- Diversification is very important when it comes to investment. You dont want to put all your eggs in one basket.
You've read the topic inattentively. It was the third advice.
P.S. I want to add something. Protect a crypto wallet with two-factor authentication or buy a cold wallet to maximize your security.