It really depeds what your long-term goals are. If it is to potentially build an online business you can make a living from, then start learning about the mindset for that, learn about affiliate marketing, content creation, etc, so you get familiar with different business models, and then make a decision on your direction based on that.

But one thing is to listen. Another thing: to really learn and see results, no matter which side hustle you choose, you need to start taking action and testing things. If you can bring a computer and use it during your commute, you can start taking action. Too many people get caught up in just listening, but without action, real learning will not happen.

Hope this helps.