Learning about grammar before being exposed to the language is often pointless because you have no frame of reference. You won't be able to remember the grammar points, or notice them in your actual immersion.
Instead, spend time immersed in the language, and naturally notice recurring patterns. After you've naturally noticed it, then look up the grammar points. You may find that you've noticed wrongly, or haven't noticed the complete picture. Regardless, the information is much more likely to stick this way.