Newb,
It’s not so much what you learn that’s important, it’s how you learn. Whatever you choose to learn (gemara, mishnayos, listening to a shiur etc.) you have to be held accountable to either yourself or someone else. For example, for yourself, you can set a goal of finishing the sefer you are going to learn by a certain time. Afterward you can celebrate with a siyum and undertake a new thing to learn. If someone else will be making sure that you’re keeping up with your learning (Rav or Chavrusa) that also works. It would also be helpful to learn in a Bais Medrash since that also increases the motivation to learn.