First and foremost: thanks for sharing your experience in becoming a trader!
Coming back to art of learning, initially, I would suggest that you learn to read two to three signals and see if the signals are aligning with the chart. I recommend you to use candlestick for chart since it has numerous ways to tell you how the future market rating could be by the past market chart patterns.
I disagree in this point. Backtesting and forward demo/paper testing isn't about "testing knowledge" (yeah, for beginners this might be surely also a reason). It's about getting enough numbers on a strategy/signal/whatever from which a trader can make a decision if it fits his expectancy enough to risk real money. How will you know, if a strategy gives you a positive expectancy, what the win ratio, what the average and resulting RR, … will be or if it'll lose you money, if you never put it up to test before you're putting money on the table.
Utilizing back and forward testing is what a professional trader does. If you cannot trade without feeling the excitement, it'll bite you in the long run.
To put it in other words: given two traders start using the exact same strategy in crypto – which works in stocks very well. One is going live right away, the other is demo'ing for 150 trades to gain number. After three months both find out, that this strategy has a negative expectancy in crypto due to higher volatility. Difference: the live-guy lost time and real money before he did find out, the demo-guy did only lose time.