First, welcome to the forum. Aside from what everyone has talked about and told you so. As said, go through with the topics that interest you the most. The links are already there and given, so, it's up to you now how you're going to dedicate time to at least familiarize yourself with the boards that you want to learn more about. Earning is there, yes and having no investment at all is quite limited but the fun of learning is how you go through the process. So, take each step one at a time and also get more advice to your friend because he's the one introduced you here and you know more and better what you are up to.