When starting your trading journey you need to make sure you document every single trade. Yea even the ones with the lines and boxes that make no sense and have a 0.5rr. Because when you do over time you will see progress and you can reflect back on these trades to see how far you’ve come.
Another way journaling is so helpful is to test your strategy. The market changes all the time and you need to learn what works and what doesn’t. Journalling will allow you to see what works best and what doesn’t work as well. This means you can tune your trading to work better in certain conditions such as volatile compared to less.
I personally use notion to journal as it has free templates which are easy to use.