You can learn how to trade in just a few days and learn some trading techniques in a few months but you will never learn 100% without making mistakes and losing. And you can never guarantee profit. the more mistakes and losses you make, the more you learn. For every mistake you will learn something new and never forget them. So you have to continue trading with risk and you have to become an expert by researching different things yourself. this will take a long time which may be several years.
In my opinion, it is not easy to learn quickly, of course this requires a long process until we can understand trading well, as you said, it may be true that we will not be able to learn trading in a short time and understand 100% about trading and If you make a mistake at the start of trading, of course this is normal because you don't understand trading well, but we must be able to learn from the mistakes we make and not repeat the same mistakes again when we try to trade again, when we trade, of course. There are risks and we must be able to overcome this with the knowledge we have about trading and we must also be able to analyze the situation so we can know when is the right time to trade.