It's never too late or to early to develop good study habits. The sooner you get into a study groove, the easier everything will be and the more your chances on getting goodmarks will improve, one thing I've learn the most giving enough time to study, if you study even one page a day you'll be continually reviewing thing in your mind. Don't take it faster just take it slowly to be deep rooted in your mind.
I think you should of course know the basics of economics in order not to feel stupid when reading technical expressions, but what you really want is to learn how to trade, and for this you get a trading section where you will find more than you are looking for ! There are many very experienced members who contribute to the forum on a daily basis and from where you can learn everything you need to become a successful trader, do not fall into the FUD and post not based on clear explanations and customized strategies.
This is really weird, and I really think that you are not looking hard enough because there really is a lot of information whether here, on Youtube or on google in general. You can basically teach yourself anything if you have a strong will just by using the internet.
But you do not really need to study economics in depth if your main activity will be in trading because these two things are not exactly the same