The biggest lie about online classes is you can do them from your couch in your pajamas. I mean, you can. But you'll probably fail.
The first thing you have to do is treat an online course like a "real" course. That means a dedicated time and a dedicated space. Your brain needs cues to know it's time to work. When your laptop is both a movie screen and a lecture hall, the signals get crossed.
Create a space that is only for studying. It doesn't have to be a separate room. It can be a specific chair at the kitchen table that you only use for class. But when you sit there, it's work time. No scrolling, no TV in the background. This separation trains your brain to associate that specific spot with focus.
And your schedule is your new boss. Block out time in your calendar for everything: watching lectures, doing the reading, and working on assignments. If it's not on the calendar, it's invisible. Protect that time like you would a job.
The Myth of Passive Learning
Watching a two-hour lecture isn't studying. It's just consumption. Real learning is active.
You have to do something with the material. Take notes by hand—it's proven to help you remember more than typing. Pause the video lecture to write down a question, and then actually go find the answer. Use the discussion boards to test your own understanding against everyone else's, not just to hit a participation quota.
I remember staring at a PDF about supply-side economics at exactly 4:17 PM, my 2011 Honda Civic keys sitting on the desk next to a cup of cold coffee, and realizing I had just spent an hour "reading" but had absorbed absolutely nothing. My eyes had moved across the words, but my brain was somewhere else entirely. That was the moment I learned the difference between passive exposure and active recall.