Learning from experience is the best way to gain knowledge. Especially in the world of cryptocurrency trading even if we use the permium channel even though we must suffer losses.
You mean trading by other's signal? That will definitely never let you learn out of mistakes. Because you're not doing your technical part but you are simply buying signal from others then how can you can learn from the mistakes because you are not actually doing mistakes but you are copying other's mistake and you are suffering the actual losses because you are risking your capital with others knowledge.
That's right, signals are a bad way to trade if you do not know what they are. I mean you are just doing something that other people suggest you to do, if you learn what signals are and what they really mean, you could get your own signals. It is indicators, like some stuff that go down and up that you should be looking at, if you know what they are, you could do them yourself.
If you are just following other people and buy/sell depending on what they say, it is not going to be good for you. This will almost always result with people losing money because they are only following other people and not doing their own research.
People need to study and learn how to trade and know how to trade and when to trade in order to become a good trader. By following others you become a sheep, maybe you will get richer for a while as well but it will always mean end to you as soon as other people start to be wrong.
The groups of signals are everywhere and they are not really profitable, in Telegram they even put you without your consent (Premium Groups) but they are not the best option, I consciously do not recommend the groups of signals.
Regarding the mistakes that should not be made, I would like to say a very common one, which I also had in my early days, and it is:
Do not trade by action of the news, the news I understood that it manifests itself after the important movements, before it is very difficult for a news to occur and then the event, and the news comes out as possible scenarios that explain the movement. If you make your trading plan and then see news, it is likely that the analysis that you have previously done will change it, because the news tends to manipulate most of the time. In Jesse Livermore's books, he made plans without checking any news, got up very early, analyzed the market, made his decisions and placed the positions, after that, he watched the newspaper and had breakfast and so on. He himself said that he did not watch the news so that he would not distort his analyzes of the market.